The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > General Truck Forums > Engine & Drivetrain > Diesel Conversions

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 07-19-2015, 09:29 PM   #1
BK4020
Registered User
 
Join Date: Jun 2015
Location: Brandon, SD
Posts: 12
84 GMC straight 6 repower

So been lurking on this site for awhile checking out all of your guys builds. Finally decided to start a thread on my project here, been gathering parts here and there for the past 2 years when the price was right to do this swap. Right now the plan is a 97 215hp 12 valve with an nv4500 behind it going into an 84 gmc pickup that will be put on an 87 v3500 frame. The engine and trans are suppoused to have 140,000 on them, I've got into the transmission already and it looks really good inside. Had the engine running on the floor and starts up and runs good with very little blow by, so I'm hoping the combo has many miles left in it. Bought the 84 GMC 1500 from a friend of mine, it is very clean and has almost no rust, which is not very typical here in the Midwest. Bought the 87 1 ton not running with no box or bed, it had a 350, 4 spd, np205 in it when I got it. So now hopefully my pictures come up!
Attached Images
     
BK4020 is offline   Reply With Quote
Old 07-19-2015, 09:45 PM   #2
BK4020
Registered User
 
Join Date: Jun 2015
Location: Brandon, SD
Posts: 12
Re: 84 GMC straight 6 repower

Also ended up buying a 91 1st gen dodge, the guy didn't want to part it out so ended up buying the whole pickup minus the box. I'm using the t-case out of it, I've already pulled it out, tore it down and replaced all the bearings and seals. Everything else looked really good inside so that's atleast done now. I've pulled everything I don't want off the 87 frame that I don't want so atleast that's ready to be rolled in the shop when the time comes. I nabbed a B & W turnover ball from a 02 Ford so I plan on getting that fabbed in too. I wanted something to pull the trailer to get other projects home and a toy to play with and start cranking up when she's up and running. Once harvest is done and a few other projects get done I hope to seriously start in on this thing and get the body swapped and the engine and trans in.
Attached Images
     
BK4020 is offline   Reply With Quote
Old 07-19-2015, 10:04 PM   #3
6BT 56
Registered User
 
6BT 56's Avatar
 
Join Date: Dec 2012
Location: Coldwater On. Canada
Posts: 551
Re: 84 GMC straight 6 repower

Looks like a great build to me . Looking forward to following along . I have the same bunch of parts kicking around waiting for me to pull the pin . Not to sure what direction to head. Get to work so I can use you for inspiration . Lol.
__________________
56 gmc 4X4 Cummins 5 spd 60F 70R
2005 Ram 3500 DRW cummins 4X4.
2006 Conolift 9/15. 2011 F 350 winter beater
New 2018 ram 3500 drw 4x4. Makes my 2005 Look as if it's been running on 4 cyl since new !
My Build http://67-72chevytrucks.com/vboard/s...d.php?t=556908
6BT 56 is offline   Reply With Quote
Old 07-19-2015, 10:19 PM   #4
BK4020
Registered User
 
Join Date: Jun 2015
Location: Brandon, SD
Posts: 12
Re: 84 GMC straight 6 repower

Yeah I've wanted to do this for quite awhile now, got 2 tractors to get done here then I'm full force on this mad scientist project! Got most of the big parts rounded up, but don't know what to do for a rear axle yet. Ring gear on the 14 bolt is junk and is 4.56 gears if I remember right. The axle in the 1 st gen dodge (dana 60?) is 3.54 but the pinion crapped its pants. From the research I've done a lot of guys use dana 80's when they start cranking these units up sooo, is it worth rebuilding the 1st gen dodge rear end or look for a dana 80 that I can bolt in? I plan to pull the trailer quite a bit so looking for opinions.
__________________
84 gmc 1500
BK4020 is offline   Reply With Quote
Old 07-19-2015, 10:36 PM   #5
6BT 56
Registered User
 
6BT 56's Avatar
 
Join Date: Dec 2012
Location: Coldwater On. Canada
Posts: 551
Re: 84 GMC straight 6 repower

I have had a few diesel dodges and all of them have been in the 3:55 to 3:73 ratio range. A great gear for these engines . The 70 rear in that dodge should work well if you fix it up. And the dodge Dana 60 front will bolt in no prob. My 56 has all the driveline your blue dodge has swapped into it.
__________________
56 gmc 4X4 Cummins 5 spd 60F 70R
2005 Ram 3500 DRW cummins 4X4.
2006 Conolift 9/15. 2011 F 350 winter beater
New 2018 ram 3500 drw 4x4. Makes my 2005 Look as if it's been running on 4 cyl since new !
My Build http://67-72chevytrucks.com/vboard/s...d.php?t=556908
6BT 56 is offline   Reply With Quote
Old 07-20-2015, 08:28 PM   #6
Dieselwrencher
6>8 Plugless........
 
Dieselwrencher's Avatar
 
Join Date: Sep 2007
Location: Prairie City, Ia
Posts: 17,133
Re: 84 GMC straight 6 repower

Welcome to the site, and nice looking project! You definitely have some good parts there! My 76 has a D70 rear and I'm just going to run it until it blows. I typically like to run a D80 for the larger brakes, and strength. But, I don't have anymore, and I need other things more importantly. I built a couple customer trucks that have 650hp+ engines in them and the D70's have been taking their abusing just fine. Also, I built a 88 V2500 suburban and used the Dodge 70 from the donor. The owner hauls a heavy dump trailer loaded pretty heavy, it has 35's and 3:54's, and as far as I know, it's still going strong. So I figure I can make this D70 last a while too.
__________________
Ryan
1972 Chevy Longhorn K30 Cheyenne Super, 359 Inline 6 cylinder, Auto Trans, Tilt, Diesel Tach/Vach, Buckets, Rare Rear 4-link and air ride option Build Thread
1972 GMC Sierra Grande Longhorn 4x4
1972 Chevy Cheyenne Super K20 Long Step side tilt, tach, tow hooks, AC, 350 4 speed
1972 C10 Suburban Custom Deluxe
1969 Chevy milk truck
1971 Camaro RS 5.3 BTR STG3 Cam Super T10
1940 Ford 354 Hemi 46RH Ford 9" on air ride huge project


Tired of spark plugs? Check this out.
Dieselwrencher is offline   Reply With Quote
Old 07-20-2015, 11:14 PM   #7
BK4020
Registered User
 
Join Date: Jun 2015
Location: Brandon, SD
Posts: 12
Re: 84 GMC straight 6 repower

Ok, sweet sounds like that 70 should be fine for me, hopefully plan and rebuild it then when I get it rolling around here. Thanks again for the info guys, there is some awesome builds on here and I need to do some more research. Kind of a newb when it comes to some of this pickup suspension stuff, usually am messing around with the green and yellow projects that live in the dirt most of time.
__________________
84 gmc 1500
BK4020 is offline   Reply With Quote
Old 07-20-2015, 11:32 PM   #8
6BT 56
Registered User
 
6BT 56's Avatar
 
Join Date: Dec 2012
Location: Coldwater On. Canada
Posts: 551
Re: 84 GMC straight 6 repower

Green and yellow is good two. Feel free to post any cool pics of that stuff aswell. After all it's your thread ! I just went the other day to look at a nice 06 6415. Nice tractor , but with 10500 hr showing I think he was asking too much $$$
__________________
56 gmc 4X4 Cummins 5 spd 60F 70R
2005 Ram 3500 DRW cummins 4X4.
2006 Conolift 9/15. 2011 F 350 winter beater
New 2018 ram 3500 drw 4x4. Makes my 2005 Look as if it's been running on 4 cyl since new !
My Build http://67-72chevytrucks.com/vboard/s...d.php?t=556908
6BT 56 is offline   Reply With Quote
Old 07-21-2015, 03:18 PM   #9
Dieselwrencher
6>8 Plugless........
 
Dieselwrencher's Avatar
 
Join Date: Sep 2007
Location: Prairie City, Ia
Posts: 17,133
Re: 84 GMC straight 6 repower

I looked at a 720 a few weeks ago that was stuck and in worse shape than my old A. I got shell shocked when the guy threw a $3500 price on it. I told him thanks and have a good one. Haha
__________________
Ryan
1972 Chevy Longhorn K30 Cheyenne Super, 359 Inline 6 cylinder, Auto Trans, Tilt, Diesel Tach/Vach, Buckets, Rare Rear 4-link and air ride option Build Thread
1972 GMC Sierra Grande Longhorn 4x4
1972 Chevy Cheyenne Super K20 Long Step side tilt, tach, tow hooks, AC, 350 4 speed
1972 C10 Suburban Custom Deluxe
1969 Chevy milk truck
1971 Camaro RS 5.3 BTR STG3 Cam Super T10
1940 Ford 354 Hemi 46RH Ford 9" on air ride huge project


Tired of spark plugs? Check this out.
Dieselwrencher is offline   Reply With Quote
Old 07-21-2015, 05:39 PM   #10
BK4020
Registered User
 
Join Date: Jun 2015
Location: Brandon, SD
Posts: 12
Re: 84 GMC straight 6 repower

Quote:
Originally Posted by Dieselwrencher View Post
I looked at a 720 a few weeks ago that was stuck and in worse shape than my old A. I got shell shocked when the guy threw a $3500 price on it. I told him thanks and have a good one. Haha
Haha yeah that seems like a bit much, around here they seem to bring a lot running or not, gas or diesel. I'll admit an electric start diesel would be kick ass one day though.

So my dad and I have been working on this thing since last fall. It's a 1966 John Deere 2510 had a 180 cubic inch gas in it originally, it actually didnt run to bad once we got it running but we acquired a 239 cubic inch 4 cylinder diesel that would bolt right in, and ohh yeah it has a turbo on it! So went through the front end, all the throttle and shift linkage, differential, steering motor, final drives, wiring, hyd. pump, clutch, and everything else except the transmission and steering valve. Finally got it all together and running took it out this spring and got it hot for the first time, found that the block was cracked from the water jacket to the outside. Someone had left water in it over the winter at one time and made a 3 inch crack that only would seep a little once it got warmed up. It was in a horrible spot right by the injection pump and none of us ever noticed it. So, the barley pops started flowing early that saturday afternoon, haha.

We decided to dyno it before we tore the engine down to see how many ponies it actually had. Came away with 90 hp and 835 ft. lbs. of torque at the pto, originally the gas engine shouldve made around 50 hp so I was pretty happy with that. Pto clutch held just fine, I turned the pump up 1/4 turn and is maxed out now, I do want to tear the pump apart and see if i can get some more fuel out of it but we'll see. Long story since then, but we just got a different block back from the machinist last week, so now its going back together again. Have a few other things to finish up on it then paint.
Attached Images
    
__________________
84 gmc 1500
BK4020 is offline   Reply With Quote
Old 07-21-2015, 06:47 PM   #11
COS399
Registered User
 
COS399's Avatar
 
Join Date: Dec 2013
Location: Northern, MT
Posts: 569
Re: 84 GMC straight 6 repower

Welcome. Looks like it's gonna be a nice truck. I'm in!
__________________

1987 GMC R2500 SC 454 T400
1988 Chevy R30 CC DRW 12 valve Cummins NV4500 GearVendors
COS399 is offline   Reply With Quote
Old 07-21-2015, 11:02 PM   #12
6BT 56
Registered User
 
6BT 56's Avatar
 
Join Date: Dec 2012
Location: Coldwater On. Canada
Posts: 551
Re: 84 GMC straight 6 repower

That's a cool old tractor. I'm just trying to get up the stones to split my 5600 ford to do a eng job. Hopefully I will do it this winter . Although it's kinda hard to get motivated to take ur one tractor with a cab apart during snow blowing season. Bowing snow with my open 1200 David brown isn't my idea of fun .
__________________
56 gmc 4X4 Cummins 5 spd 60F 70R
2005 Ram 3500 DRW cummins 4X4.
2006 Conolift 9/15. 2011 F 350 winter beater
New 2018 ram 3500 drw 4x4. Makes my 2005 Look as if it's been running on 4 cyl since new !
My Build http://67-72chevytrucks.com/vboard/s...d.php?t=556908
6BT 56 is offline   Reply With Quote
Old 07-22-2015, 09:21 PM   #13
Dieselwrencher
6>8 Plugless........
 
Dieselwrencher's Avatar
 
Join Date: Sep 2007
Location: Prairie City, Ia
Posts: 17,133
Re: 84 GMC straight 6 repower

Nice tractor, really stinks about the crack. I have your kind of luck too! Haha I bought a 52 A a couple years ago to use to brush hog. I got a 3pt and got it installed to find out the tractor had bad PTO drive gears. Of course you have to split the tractor to do it too. So I got a Super H to mpw with. Maybe someday I'll fix the hydros on the Deere. Or just turn it into a puller for the kids.
__________________
Ryan
1972 Chevy Longhorn K30 Cheyenne Super, 359 Inline 6 cylinder, Auto Trans, Tilt, Diesel Tach/Vach, Buckets, Rare Rear 4-link and air ride option Build Thread
1972 GMC Sierra Grande Longhorn 4x4
1972 Chevy Cheyenne Super K20 Long Step side tilt, tach, tow hooks, AC, 350 4 speed
1972 C10 Suburban Custom Deluxe
1969 Chevy milk truck
1971 Camaro RS 5.3 BTR STG3 Cam Super T10
1940 Ford 354 Hemi 46RH Ford 9" on air ride huge project


Tired of spark plugs? Check this out.
Dieselwrencher is offline   Reply With Quote
Old 07-24-2015, 07:56 PM   #14
BK4020
Registered User
 
Join Date: Jun 2015
Location: Brandon, SD
Posts: 12
Re: 84 GMC straight 6 repower

Quote:
Originally Posted by Dieselwrencher View Post
Nice tractor, really stinks about the crack. I have your kind of luck too! Haha I bought a 52 A a couple years ago to use to brush hog. I got a 3pt and got it installed to find out the tractor had bad PTO drive gears. Of course you have to split the tractor to do it too. So I got a Super H to mpw with. Maybe someday I'll fix the hydros on the Deere. Or just turn it into a puller for the kids.
Yeah that sucks about your A, would be a little bit of screwing around to fix that too. It seems with these old tractors when you open them up or tear one thing apart most things are "is it worth getting new or fixing it for what I'll be using it for?" And the parts always seem to be going up too.

Anyways had a little bit of time to screw around with transmission and transfercase, kind of mocked up some cardboard to make a mount for the tcase shifter handle. Don't know if I like it yet. I thought about drilling and taping that big cast iron boss that protrudes out the side of the casing on the right rear side but then I questioned if that would hold up. Either the cast iron would get to thin or the pivot pin would be to small if I did that. Havent looked at to many other setups, has anybody done this?

Also ordered the 5th gear nut lock for the nv4500 that pretty much gurantees the nut cant back off. I didn't pull the nut off but I assume its the stock mainshaft, with the stock mainshaft would I have to worry about it failing not being fully splined or is the 5th gear nut usually just the problem? Hoping to get the tractor engine back together tonight and if everything goes right, back in the tractor tomorrow. I don't know about everyone else but its pretty hot and humid here.
Attached Images
     
__________________
84 gmc 1500
BK4020 is offline   Reply With Quote
Old 07-24-2015, 10:26 PM   #15
6BT 56
Registered User
 
6BT 56's Avatar
 
Join Date: Dec 2012
Location: Coldwater On. Canada
Posts: 551
Re: 84 GMC straight 6 repower

Looking good . When I did mine I had the dodge 205 and the getrag 5 spd out of a 1 gen. I. Needed my shifter moved fwd abt 10 inches . I took the stock dodge bracket and cut it in half and spliced in some matching material cut to length and welded back together . Then I made a foot that uses a bell housing bolt for support so it dosent move around as it is quite long now . I don't recall if there are any pics on my thread or not . What handle were you using the dodge one or the k30 one ? If memory serves the gm one is a nicer shifter. Good luck with the tractor .
__________________
56 gmc 4X4 Cummins 5 spd 60F 70R
2005 Ram 3500 DRW cummins 4X4.
2006 Conolift 9/15. 2011 F 350 winter beater
New 2018 ram 3500 drw 4x4. Makes my 2005 Look as if it's been running on 4 cyl since new !
My Build http://67-72chevytrucks.com/vboard/s...d.php?t=556908
6BT 56 is offline   Reply With Quote
Old 07-30-2015, 11:10 AM   #16
burnin oil
Registered User
 
Join Date: Jan 2013
Location: Eastern TN
Posts: 1,919
Re: 84 GMC straight 6 repower

I missed the axle conversation but a little note about the Dodge D80. It is actually only a D80 pumpkin with D70 outers. If you look at the axle tubes you can see where they neck down at the ends. They also use the same axle shafts as the 70. Still it is one tough axle. The 3.55 gears work really well for all but the heaviest towing so I wouldn't worry there. My dads 2500 has the 4.10s and tends to pull in a little better milage empty or towing. That's not a fair comparison as mine is a 12v standard cab and his is a 24v ext cab short box. Both 4x4s with manual transmissions. If I was building the truck for some decent towing and not a lot of 70mph driving it would be 4.10s.
burnin oil is offline   Reply With Quote
Old 08-01-2015, 05:16 PM   #17
ryanroo
Senior Member
 
ryanroo's Avatar
 
Join Date: Apr 2004
Location: sw colorado
Posts: 2,720
Re: 84 GMC straight 6 repower

Sweet build, I wanna watch!
__________________
72 K20 12v build
72 K20 "parts truck"

ryanroo is offline   Reply With Quote
Old 08-02-2015, 12:56 PM   #18
BK4020
Registered User
 
Join Date: Jun 2015
Location: Brandon, SD
Posts: 12
Re: 84 GMC straight 6 repower

Quote:
Originally Posted by 6BT 56 View Post
Looking good . When I did mine I had the dodge 205 and the getrag 5 spd out of a 1 gen. I. Needed my shifter moved fwd abt 10 inches . I took the stock dodge bracket and cut it in half and spliced in some matching material cut to length and welded back together . Then I made a foot that uses a bell housing bolt for support so it dosent move around as it is quite long now . I don't recall if there are any pics on my thread or not . What handle were you using the dodge one or the k30 one ? If memory serves the gm one is a nicer shifter. Good luck with the tractor .
Thanks man chipping away at some stuff during my spare time. The handle I had there was the one out of the dodge. The one out of the chevy is nicer so I might use that one yet too, it seems I'm indecisive about a lot of this stuff, and don't ever get anything accomplished.
__________________
84 gmc 1500
BK4020 is offline   Reply With Quote
Old 08-02-2015, 01:32 PM   #19
BK4020
Registered User
 
Join Date: Jun 2015
Location: Brandon, SD
Posts: 12
Re: 84 GMC straight 6 repower

Quote:
Originally Posted by burnin oil View Post
I missed the axle conversation but a little note about the Dodge D80. It is actually only a D80 pumpkin with D70 outers. If you look at the axle tubes you can see where they neck down at the ends. They also use the same axle shafts as the 70. Still it is one tough axle. The 3.55 gears work really well for all but the heaviest towing so I wouldn't worry there. My dads 2500 has the 4.10s and tends to pull in a little better milage empty or towing. That's not a fair comparison as mine is a 12v standard cab and his is a 24v ext cab short box. Both 4x4s with manual transmissions. If I was building the truck for some decent towing and not a lot of 70mph driving it would be 4.10s.
Yeah I'd like to be able to put it down at 75 and cruise down the interstate at a decent rpm. We also have a 32 ft. gooseneck trailer for hauling random stuff around, loaded down it can really make my dads 04 duramax work. It would be nice to be able to lug that around so I don't know if that's asking to much out of this pickup, being a shorter wheel base and single rear wheel. I'll have to see I guess.
__________________
84 gmc 1500
BK4020 is offline   Reply With Quote
Old 08-02-2015, 01:34 PM   #20
6BT 56
Registered User
 
6BT 56's Avatar
 
Join Date: Dec 2012
Location: Coldwater On. Canada
Posts: 551
Re: 84 GMC straight 6 repower

Looks like you have a great stash of parts / parts trucks to work with . You will have many avenues available to you. I just bought a parts truck like the one you have for a body donor. Such a nice truck. The po parked it in the grass and downhill it went .
__________________
56 gmc 4X4 Cummins 5 spd 60F 70R
2005 Ram 3500 DRW cummins 4X4.
2006 Conolift 9/15. 2011 F 350 winter beater
New 2018 ram 3500 drw 4x4. Makes my 2005 Look as if it's been running on 4 cyl since new !
My Build http://67-72chevytrucks.com/vboard/s...d.php?t=556908
6BT 56 is offline   Reply With Quote
Old 08-03-2015, 09:01 PM   #21
Dieselwrencher
6>8 Plugless........
 
Dieselwrencher's Avatar
 
Join Date: Sep 2007
Location: Prairie City, Ia
Posts: 17,133
Re: 84 GMC straight 6 repower

Back to your trans 5th gear question. The only thing I can see that could cause an issue, is if your main shaft is still stock. Pre 98 Dodge NV4500's did not have fully splined main shafts and can be an issue. But, with that 5th gear locking collar, it should be fine.
__________________
Ryan
1972 Chevy Longhorn K30 Cheyenne Super, 359 Inline 6 cylinder, Auto Trans, Tilt, Diesel Tach/Vach, Buckets, Rare Rear 4-link and air ride option Build Thread
1972 GMC Sierra Grande Longhorn 4x4
1972 Chevy Cheyenne Super K20 Long Step side tilt, tach, tow hooks, AC, 350 4 speed
1972 C10 Suburban Custom Deluxe
1969 Chevy milk truck
1971 Camaro RS 5.3 BTR STG3 Cam Super T10
1940 Ford 354 Hemi 46RH Ford 9" on air ride huge project


Tired of spark plugs? Check this out.
Dieselwrencher is offline   Reply With Quote
Old 10-06-2015, 12:00 AM   #22
BK4020
Registered User
 
Join Date: Jun 2015
Location: Brandon, SD
Posts: 12
Re: 84 GMC straight 6 repower

Haven't got much to update on the project right now, been busy with harvest and getting these tractors finished up. Got a few things ordered though, governor springs for the injection pump, 1 3/8" input shaft kit for the nv4500, and ARP head studs for the 12 valve. Other than that not a whole lot, acquired a beast of an engine stand last week! Actually got 2 of them for a sweet deal, sold one to a friend and he is going to take care of getting adapter plates made for me, for Cummins and John Deere blocks to start off with. Been looking at building/buying one for awhile when I came across these, should be handy when I go through the 5.9. Not much else for progress, once the corn is out should have a lot more time to play.
Attached Images
  
__________________
84 gmc 1500
BK4020 is offline   Reply With Quote
Old 10-06-2015, 08:53 PM   #23
Dieselwrencher
6>8 Plugless........
 
Dieselwrencher's Avatar
 
Join Date: Sep 2007
Location: Prairie City, Ia
Posts: 17,133
Re: 84 GMC straight 6 repower

That is an awesome engine stand! Nice score!
__________________
Ryan
1972 Chevy Longhorn K30 Cheyenne Super, 359 Inline 6 cylinder, Auto Trans, Tilt, Diesel Tach/Vach, Buckets, Rare Rear 4-link and air ride option Build Thread
1972 GMC Sierra Grande Longhorn 4x4
1972 Chevy Cheyenne Super K20 Long Step side tilt, tach, tow hooks, AC, 350 4 speed
1972 C10 Suburban Custom Deluxe
1969 Chevy milk truck
1971 Camaro RS 5.3 BTR STG3 Cam Super T10
1940 Ford 354 Hemi 46RH Ford 9" on air ride huge project


Tired of spark plugs? Check this out.
Dieselwrencher is offline   Reply With Quote
Old 10-07-2015, 11:31 PM   #24
BK4020
Registered User
 
Join Date: Jun 2015
Location: Brandon, SD
Posts: 12
Re: 84 GMC straight 6 repower

Quote:
Originally Posted by Dieselwrencher View Post
That is an awesome engine stand! Nice score!
Yeah and its heavyyy duty! Shop I got them from used them for 6-92 detroits and 8.3 cummins mostly, so should be plenty good for what I plan to use them for. Looked at the OTC ones and they bring stupid money even for used ones, but I've used them before and they are flippin nice.
__________________
84 gmc 1500
BK4020 is offline   Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 07:32 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright 1997-2022 67-72chevytrucks.com