Re: GMC V-12 powered '91 Chev crewcab
 

Got some questions:

#1: What's the highest ratio rear end gears available for Chevy 1 tons? I'd like to get up as high as 3 if possible.

#2: Would the '78? cab/chassis complete rear end be a direct swap out to the '91 dually FRAME? or is the frame widths different?

With a 2400rpm max on the v-12, I hope to use a 5spd overdrive tranny and increase the rearend ratio enough to get 80mph @2400.
I have a 3spd over auxillary tranny available, but would like to stay away from the extra driveshafts, length in the drive line, and keep the whole drive line as simple as possible.

It's for sure I have no worries about torque or power to pull high ratios, but need gears stout enough to stand a 20,000#max cgvw occasionally, so trying to stay with all 1 ton components.

Maybe, just maybe, this week we can fire the old motor, and then start the search for clutch/driveline. I want to have all that matched up and assembled in the shop floor before attempting to sit the package in a frame. I'm guessing all combined is going to weigh 2,000# or more.

Couldn't resist: My son noticed yesterday my dog (Scooter) would match my truck.
I guaroontee the pic hasn't been messed with, he's half Beagle and half mini-weenie. He had an encounter with a rattlesnake awhile back, (Rattlesnake won) but is ok now.

Enough trivia for today
Thanks,
Cayoterun

Re: GMC V-12 powered '91 Chev crewcab
 

3.21's are as low numerically you can get for the 14 bolt. I put 3.21's in my 88. The spring pads are alot further apart on my '88 than on a 73-87 one ton. 73-87 3/4 tons have spring pads further apart than the same years of one tons, but still nowhere near the 88-up. Shock mounts are different on 88-up also.

Re: GMC V-12 powered '91 Chev crewcab
 

Good News: I checked the gear calculator and a 5spd over/w 3.21 gears gives 81mph @ 2400 & 64mph@1900rpm. That gives inter-state speeds, so that's plenty for me.

I think I want the narrow frame for this as it would give more options of bed type we use. Bed would go on frame last.
We may be stretching the '78? flatbed frame instead of the '91.

I suppose you saw all the scenic wonders of western Ks. by now?
Thanks,
Cayoterun

Re: GMC V-12 powered '91 Chev crewcab
 

It's like a big desert compared to around here. I don't think I seen any groundwater until at least 100 miles east of Garden City. Dry river beds, no ponds... yet a local says they have large deer around there. I don't see how, when there is no water, or trees for cover. I never thought there were many trees here, but I think there are more trees within a 5 mile radius of my house than a 100 mile radius of that town. The things that really stuck out were LPG powered big blocks for well pumps instead of diesel, and a liquor store on every block :crazy:

I found it odd when I moved here, only 140 miles from my hometown. A spring in my yard that runs 365 days a year, and crawdads that come up thru holes in my yard. I find it fascinating how much things change with such little distance.

Re: GMC V-12 powered '91 Chev crewcab
 

My son-in-law got his deer last night here on the place. It was a white-tail and weighed 140#, field dressed. He was kinda
disappointed, as he has killed as big as 180# field dressed. Some bigger have been killed.
Mule deer are some bigger than that.
How does that compare to east of here?
Cayoterun

Re: GMC V-12 powered '91 Chev crewcab
 

Dunno, I'm not a deerhunter- unless you count the one I almost got with my pickup last week. It was funny- a small buck come up out of the RH ditch, just missed the bedside of my truck as I went by, and jumped up & cleared my empty car trailer just catching its hoofs on the LH trailer fender. It did 1/2 a barrel roll, landed on its side on the highway & jumped up & took off. They are thick around here. Can't make a trip to town without seeing a dead one on the highway.

Re: GMC V-12 powered '91 Chev crewcab
 

Have you thought about maybe using a crew cab frame, and just sitting the cab back towards the bed? Just an idea that struck me...

Re: GMC V-12 powered '91 Chev crewcab
 

Are you thinking of doing that with the crewcab cab? If so, what would it look like.
The main things that's pulled me toward the '62 GMC are sentiment, (first owner good friend), current title and tags, and year model is close to when motor was new ('64).
I measured the frame and wheel widths on the '79 yellow/black flatbed and the wheels and frame are about 9" narrower than a dually. I'm thinking now, I'd like the narrow set-up better.
I'm bouncing around like a ping-pong ball on what to mount the motor/tranny in, so all suggestions are appreciated.
I'm just now ready to start trying to find clutch/tranny/gear ratios that will match inter-state speeds and fit on the motor, which looks like it's not going to be easy. I'm learning these motors are pretty well a breed all their own.
If someone out there has some 3.21 (or close) gears they'd sell for a 14bolt chevy rear end, I'd sure be interested.
Thanks,
Cayoterun

Re: GMC V-12 powered '91 Chev crewcab
 

702 V-12 for sale on the 6066GMCguy site from a truck. Site message# 33586. Lots of pics
Cayoterun

Re: GMC V-12 powered '91 Chev crewcab
 

No, I'm not thinking of doing it with the crew, I just thought if you could score a crewcab frame somewhere, it might save you some framework due to the extra length.

If you were to find, say, a 73-87 crew frame, you could mount your bed where it goes on the frame, then add your cab where it goes in relation to the bed, and then you'd have a whole lotta frame left forward of the firewall to get your engine mounted. The hard part would be stretching the fenders and hood. The frame would be uncut, really, so there wouldn't be the headaches of making sure everything is OK for it to go down the road straight. Just thought it might save you some time, money and headache.

Re: GMC V-12 powered '91 Chev crewcab
 

I gotcha'-- Measure and work from back to front. Then since the hood and clip has to be stretched, fill in the remaining space. Right?
I assume from your last post, they made crewcabs back as far as '73. I don't remember. That's where you guys help get my head outside-the-box. We don't have hardly any salvage yards here, so I'm limited to farmers pastures mostly.

The whole neighborhood is getting caught up in this old motor, but since they hav'nt been used for 20+ yrs, we've all forgotten how to work on them, mainly the timing, even with service manuals, it's still tricky.
Back then, they could jerk a distributor, fix it, have it back running in an hr, holding a flashlight in their mouths at 3:00 in the morning. We are getting good laughs at how old we're getting.
Thanks for a new look at this,
also thanks to all of you guys for having patience with this old guy that's had a stroke, left with limited vision, forgetful, crippled up, but thankful for the can dos, not the can't dos. Life is good.
Cayoterun

Re: GMC V-12 powered '91 Chev crewcab
 

THE DRAGON BREATHS FIRE AND THUNDER ONCE MORE!!! YEEEHAAA

Didn't let it run more than 2-3 seconds. no water & want to try to get video as it burns all the oil, mud dobbers, and dead mice out I missed.
Cayoterun

Maybe short video Sunday if Son is off work.

I had to tell somebody,---- my wife didn't seem too impressed.

Re: GMC V-12 powered '91 Chev crewcab
 

Hot Damn!

Re: GMC V-12 powered '91 Chev crewcab
 

Congrats!! I have a suggestion for a name for it. Balaur. It's a multi-headed dragon of mythical lore. Thought it was fitting.

Re: GMC V-12 powered '91 Chev crewcab
 

Way to go!

As I read your post, I pictured that mad scientist running around his lab yelling "IT'S ALIVE! IT'S ALIVE!"

We definately wanna see a video clip!

:cong: :clap:

Re: GMC V-12 powered '91 Chev crewcab
 

Mickey D, I hope Balaur ain't some dirty word in some strange language, cause it might show up in some pics!

I admit it was a good feeling, brought back lots of memories from the past almost 43 yrs since I heard her fire the first time. Lots of changes and water under the bridge since then. I lived and worked for the first owner as a kid, treated me like a son, taught me much, even offered to help me thru college--they're gone now. Lots of great people pass thru our lives. 'nuff of that.
Cayoterun

Re: GMC V-12 powered '91 Chev crewcab
 

better go like a mad sientist saying its alive its alive then runnin around like dexter screaming my hair is on fire my hair is on fire

Re: GMC V-12 powered '91 Chev crewcab
 

No hair problem---Ain't got none
Cayoterun

Re: GMC V-12 powered '91 Chev crewcab
 

That's awesome! Can't wait to see/hear it run.

Re: GMC V-12 powered '91 Chev crewcab
 

BALAUR, attempted flight, low batteries, cold weather. Practicing posting videos. Failed for today. Tried 27 ways that didn't work. These motors were notorious for being hard starting.
It's name for today was-- Oh baloney.

When I scatched her name with soapstone on the surge tank, wiped the dust off, and it had anti-freeze checked 10-31-85 with tire chalk, so we know she was in service then. 21yrs not bad.
Cayoterun


http://www.youtube.com/haystack155

Re: GMC V-12 powered '91 Chev crewcab
 

Nope, not a dirty word as far as I know. Just the name of an old Romanian legend.

http://en.wikipedia.org/wiki/Balaur

I so wanted to hear that start in the video!! :(

Re: GMC V-12 powered '91 Chev crewcab
 

It says they could have up to twelve heads. I hope she isn't too evil.
I wonder if those 12 heads could be represented with 12 exhaust pipes sticking straight up.
Thanks for the name.
Cayoterun

Re: GMC V-12 powered '91 Chev crewcab
 

Ever thought of running it on propane? Theres a set of propane carbs on ebay http://cgi.ebay.com/ebaymotors/GMC-V...spagenameZWD1V

Re: GMC V-12 powered '91 Chev crewcab
 

Those are natural gas/propane carbs on it now. I put new propane diaphragms/venturas in. It had burned natural gas all it's working life. When we get a side view, you'll see the propane regulator hanging on the right side of the motor with the propane line going forward and out the shop door. We're just using a propane bottle outside for safetys sake. The fuel supply line carries tank pressure up to the regulator. Pressures up to 250# in summer. It's steel braided line.
It hasn't burned any gasoline in it's life.
I've always liked propane as fuel, but I grew up around it, too. Plan to use it if we ever get it in a truck.
Thanks,
Cayoterun

I looked at your e-bay ad, and I've never seen a set-up configured like that. That sure don't mean there's not alot around. All that was used here will look like the ones on my motor.
I have another V-12 in the shop for parts that has an after market adapter that uses one 4-barrel gas carb. Only one of those I've ever seen. This doesn't have a carb on it, just adapter.

Re: GMC V-12 powered '91 Chev crewcab
 

http://www.youtube.com/haystack155

Well, now I know how the dog feels that caught the car.----What are we gonna' do with it?

The vapor coming out the radiator outlet is not a sign the motor is hot. Probably just gunk getting hot next to cylinders in water jacket.
I was able to hold my hand on the exhaust manifold when we shut it off.
Sounded good, had 40# oil pressure and was burning propane.
I think the name just fits.
Next is rig up a temporary radiator, lots of tinkering and matching a clutch/tranny.
Thanks, everyone,
Cayoterun