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 > 47 - Current classic GM Trucks > The 1967 - 1972 Chevrolet & GMC Pickups Message Board

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 07-10-2019, 12:38 PM   #1
special-K
Special Order
 
special-K's Avatar
 
Join Date: Nov 2004
Location: Mt.Airy,MD
Posts: 69,256
K2500 w/3.54:1

What do you think? Would you want 3.54:1 ratio in a K2500/K20 with Th350 and 285/75-16s or there abouts rubber? I ask because I just opened up a Dana 60 Power-Lok I have and that's the ratio. I'm a 4.10 man from way back and I don't need to go 80 mph. Do you think the mileage gain would be significant and worth the loss of grunt? I haven't done any math, but it seems the difference in gearing would be close to O/D on the hiway. But it's all the time, not just up to speed. I do have another Dana 44 front axle to do the gear swap, so could always the 3.10 set in case I didn't like it or need it. Just pondering I guess.

* Actually, probably not like O/D. More like about half what O/D gives
__________________
"BUILDING A BETTER WAY TO SERVE THE USA"......67/72......"The New Breed" GMC

'67 C1500 Wideside Super Custom SWB: 327/M22/3.42 posi..........'The 67' (project)
'72 K2500 Wideside Sierra Custom Camper: 350/TH350/4.10 Power-Lok...'The 72' (rolling)
Tim

"Don't call me a redneck. I'm a rough cut country gentleman"

R.I.P. ~ East Side Low Life ~ El Jay ~ 72BLUZ ~ Fasteddie69 ~ Ron586
special-K is offline   Reply With Quote
Old 07-10-2019, 01:36 PM   #2
RichardJ
Registered User
 
Join Date: Apr 2010
Location: So Cal
Posts: 983
Re: K2500 w/3.54:1

Not 4wd, but in some ways, close to the same parameters.

C20, SM465, 3.54:1 DANA posi, 285/70R17, 4600# across the scales , but 292 six.
I has done light towing and often has bed full of gravel, sand, pavers, lumber. Unloaded on the open hwy, it's very comfortable at 70-75 and always with the AC on.

With the extra weight of 4wd you might want 3.73:1, but you do have a v8 and auto trans
RichardJ is offline   Reply With Quote
Old 07-10-2019, 01:47 PM   #3
MARKDTN
Registered User
 
Join Date: Jan 2011
Location: Chattanooga, TN
Posts: 1,717
Re: K2500 w/3.54:1

My '83 K20 has 3.42s and 700R4 overdrive. It was OK with the stock engine, but the Tuned-Port fuel injection really woke it up. I guess I am saying if you have an engine with some bottom end torque it will probably be fine.
__________________
'83 K20-TPI
'79 C10-ex-diesel(SOLD)
'01 Tahoe
'07 Tahoe-DD
MARKDTN is offline   Reply With Quote
Old 07-10-2019, 02:10 PM   #4
jocko
Senior Member
 
jocko's Avatar
 
Join Date: Oct 2009
Location: Burleson, TX
Posts: 15,835
Re: K2500 w/3.54:1

Agree with above statement. For occasional off road or hauling duties, 4.10 probably preferred since you said you don’t need to go 80 on the hwy. 3.54 with 285s probably about as high a gear I’d ever want to go to, if ever. 3.54 a std ratio for a big block C20 with a D60 - but I was not aware that there was a 3.54 gear available for a D44 to make a matched set(?) I think you will really notice the torque loss going from 4.10 to 3.54, which is even worse with 285s (which already provide an apparent ratio of 3.90-4.00-ish due to tire dia). Personally, I’d save the 3.54 for a future C20 or stick it in that nice SWB project
jocko is offline   Reply With Quote
Old 07-10-2019, 02:33 PM   #5
57taskforce
Registered User
 
57taskforce's Avatar
 
Join Date: Jun 2014
Location: New Mexico
Posts: 2,409
Re: K2500 w/3.54:1

If you had a 4 speed I bet you could live with it pretty decent being able to use granny to get you out of the hole better when loaded up, being you’ve got an auto I’d agree with the guys above. I’m with you Tim, I like 4:10s as well.
__________________
'57 3100 350/700r4 35x12.5's
'72 K/20 Cheyenne 350/SM465 in pieces awaiting ly6 6.0 swap. http://67-72chevytrucks.com/vboard/s...d.php?t=662879
'98 Silverado LT K2500HD ECLB Vortec 454/4l80E: 6"RCD 315/75/16's
10 Camaro 2SS/RS l99 6l80e Aqua Blue Metallic #2399
57taskforce is offline   Reply With Quote
Old 07-11-2019, 08:45 AM   #6
special-K
Special Order
 
special-K's Avatar
 
Join Date: Nov 2004
Location: Mt.Airy,MD
Posts: 69,256
Re: K2500 w/3.54:1

Yep, love my "gears", too! I'm not going this route. I bought the rear Sunday as a suspected posi because both wheels turned. Ratio was uncertain, but not to me if it was in fact from a '68 396/TH400. I opened it up yesterday and verified it is in fact a Power-Lok 3.54. Then the thoughts started rolling and I started this thread. As the day went on I decided to scrap such ideas. In into going over the original rear now. I was actually hoping this was another 4.10 for a spare.

Jocko you read my mind. I have been wanting a 3.54 Dana60 for my '67 project all along. What a dream era correct drivetrain for my era hot truck build, 327 steel crank large journal (have and built)/M22 (have)/3.54 posi Dana60. I have 3.52s & a posi for the 12-bolt as it is. Now to see if I can find parts to convert to 6-lug semi-floater!
__________________
"BUILDING A BETTER WAY TO SERVE THE USA"......67/72......"The New Breed" GMC

'67 C1500 Wideside Super Custom SWB: 327/M22/3.42 posi..........'The 67' (project)
'72 K2500 Wideside Sierra Custom Camper: 350/TH350/4.10 Power-Lok...'The 72' (rolling)
Tim

"Don't call me a redneck. I'm a rough cut country gentleman"

R.I.P. ~ East Side Low Life ~ El Jay ~ 72BLUZ ~ Fasteddie69 ~ Ron586
special-K is offline   Reply With Quote
Old 07-11-2019, 08:22 PM   #7
special-K
Special Order
 
special-K's Avatar
 
Join Date: Nov 2004
Location: Mt.Airy,MD
Posts: 69,256
Re: K2500 w/3.54:1

I run at 65 just fine. I don't like to run it at 70, which is the speed limit on the open interstate. That's the thing, it really is open interstate. You can run along in the slow lane at 55 if you want. You have to run flashers at 40. It's 6 lane, so they can pass if they don't like my speed. The other thing is, between my place and Baltimore there are the very old rural 2 lanes* running parallel on either side. I mean 45-50 (or less) stuff. I won't always live hear, but where I live I'm fine with what I have. Before I ever owned my '92, all my 8-luggers were 4.10. The '92 had 4.10s, too, w/NV4500! And that was like driving a car. Actually, my daily driver '95 Suburban has 4.10a with O/D. Boy, I really am a 4.10 man


* One is the actual "National Road" from George Washington time and the other is probably just as old and that's "Frederick Rd". I'm a in between Baltimore and Frederick.
__________________
"BUILDING A BETTER WAY TO SERVE THE USA"......67/72......"The New Breed" GMC

'67 C1500 Wideside Super Custom SWB: 327/M22/3.42 posi..........'The 67' (project)
'72 K2500 Wideside Sierra Custom Camper: 350/TH350/4.10 Power-Lok...'The 72' (rolling)
Tim

"Don't call me a redneck. I'm a rough cut country gentleman"

R.I.P. ~ East Side Low Life ~ El Jay ~ 72BLUZ ~ Fasteddie69 ~ Ron586

Last edited by special-K; 07-11-2019 at 08:34 PM.
special-K is offline   Reply With Quote
Old 07-11-2019, 09:16 PM   #8
57taskforce
Registered User
 
57taskforce's Avatar
 
Join Date: Jun 2014
Location: New Mexico
Posts: 2,409
Re: K2500 w/3.54:1

Quote:
Originally Posted by special-K View Post
I run at 65 just fine. I don't like to run it at 70, which is the speed limit on the open interstate. That's the thing, it really is open interstate. You can run along in the slow lane at 55 if you want. You have to run flashers at 40. It's 6 lane, so they can pass if they don't like my speed. The other thing is, between my place and Baltimore there are the very old rural 2 lanes* running parallel on either side. I mean 45-50 (or less) stuff. I won't always live hear, but where I live I'm fine with what I have. Before I ever owned my '92, all my 8-luggers were 4.10. The '92 had 4.10s, too, w/NV4500! And that was like driving a car. Actually, my daily driver '95 Suburban has 4.10a with O/D. Boy, I really am a 4.10 man


* One is the actual "National Road" from George Washington time and the other is probably just as old and that's "Frederick Rd". I'm a in between Baltimore and Frederick.
I used to like to drive route 9 between Leesburg and Charlestown or 9 to 671 to 340 to get to Neersville and HarpersFerry. When we lived in Neersville that was about the only way to get anywhere east... that used to be a nice drive in the old 4 speed trucks. Holy crap, the asshats were running me over at 60 when I went home a month or so ago. I cant hardly that drive any more. Its all grown up so much. A lot has changed in 5 years, (really the last 25 or 30) every year when I go back I recognize it all a little less.
__________________
'57 3100 350/700r4 35x12.5's
'72 K/20 Cheyenne 350/SM465 in pieces awaiting ly6 6.0 swap. http://67-72chevytrucks.com/vboard/s...d.php?t=662879
'98 Silverado LT K2500HD ECLB Vortec 454/4l80E: 6"RCD 315/75/16's
10 Camaro 2SS/RS l99 6l80e Aqua Blue Metallic #2399
57taskforce is offline   Reply With Quote
Old 07-11-2019, 10:31 PM   #9
special-K
Special Order
 
special-K's Avatar
 
Join Date: Nov 2004
Location: Mt.Airy,MD
Posts: 69,256
Re: K2500 w/3.54:1

Yeah, the thing in that area is there's only one road. The Charles Town area has built up so much it isn't funny. And it's all transplants rushing to get back where they can from to make the money they bring back to raise the cost of living for those who lived there since the same people had no interest. I blame overdrive transmissions!! Seriously. They don't save fuel, they have allowed urban sprawl to spread farther out and people are driving faster to get from point A to point B because they are farther apart. People are commuting 1.5 hours one way and that's ideal conditions, no accidents, or other rubber-neckin' idiot bs.

I can drive to Carlisle and never hit the hiway and doesn't take much longer. I drive through the country to the PA line to hit US15 minimum anyway. All hiway is much less direct. And 15 is a nice drive with sparse traffic.

I'll drive to Hedgesville, Berkley Springs, all the way to Cumberland, up to Pittsburg on old 2-lanes. I drive to my sister's between Front Royal and Luray in my '72 all the time. Every year I drive it to Clearbrook in Sept for the antique truck show. Then we drive to Berryville Saturday night after the show for the Watermelon Festival... Yeehaw!!

That's one good thing about the old back east... old windy roads up and down the grades

Any of this look familiar? Last two are up at my sister's place.
Attached Images
     
__________________
"BUILDING A BETTER WAY TO SERVE THE USA"......67/72......"The New Breed" GMC

'67 C1500 Wideside Super Custom SWB: 327/M22/3.42 posi..........'The 67' (project)
'72 K2500 Wideside Sierra Custom Camper: 350/TH350/4.10 Power-Lok...'The 72' (rolling)
Tim

"Don't call me a redneck. I'm a rough cut country gentleman"

R.I.P. ~ East Side Low Life ~ El Jay ~ 72BLUZ ~ Fasteddie69 ~ Ron586

Last edited by special-K; 07-11-2019 at 10:46 PM.
special-K is offline   Reply With Quote
Old 07-11-2019, 10:42 PM   #10
special-K
Special Order
 
special-K's Avatar
 
Join Date: Nov 2004
Location: Mt.Airy,MD
Posts: 69,256
Re: K2500 w/3.54:1

I guess since I'm not going with hiways gears I'm showing where I go without hiway gears. If I had to run consistently at 65 I would want better gearing. I practice avoidance and that gets old, too, when it's everyday. I just want to get there and get home the quickest way

All pictures are from the same weekend
Attached Images
     
__________________
"BUILDING A BETTER WAY TO SERVE THE USA"......67/72......"The New Breed" GMC

'67 C1500 Wideside Super Custom SWB: 327/M22/3.42 posi..........'The 67' (project)
'72 K2500 Wideside Sierra Custom Camper: 350/TH350/4.10 Power-Lok...'The 72' (rolling)
Tim

"Don't call me a redneck. I'm a rough cut country gentleman"

R.I.P. ~ East Side Low Life ~ El Jay ~ 72BLUZ ~ Fasteddie69 ~ Ron586

Last edited by special-K; 07-11-2019 at 10:51 PM.
special-K 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 03:56 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2019, vBulletin Solutions Inc.
Copyright 1997-2013 67-72chevytrucks.com