![]() |
![]() |
#26 |
Moderator
![]() Join Date: May 2007
Location: Southern Cal
Posts: 20,006
|
Re: 3:07 Rear End
I believe truck is 3.07, car 3.08. Longhorn Man used to correct everyone on here when the subject came up as it was a pet peeve of his
![]()
__________________
1972 C/10 Cheyenne Super SWB. Restored, loaded, slammed. 1968 C/10 50th Anniversary LWB. Unrestored, stock, daily driver/work truck. RIP ElJay RIP 67ChevyRedneck RIP Grumpy Old Man |
![]() |
![]() |
![]() |
#27 | |
Registered User
Join Date: Aug 2006
Location: Redmond, WA
Posts: 6,332
|
Re: 3:07 Rear End
Quote:
For example: A 3.08 gearset is 12/37 which is 3.0833333… A 3.07 gearset is 13/40 which is 3.07692307… You could have other setups as well, like in a larger rear end you could have a 14-43 setup which would give you 3.0714
__________________
1970 GMC Sierra Grande Custom Camper - Built, not Bought 1969 Pontiac 2+2 427/390 4-speed Coupe 1969 Pontiac 2+2 427/390 4-speed Convertible |
|
![]() |
![]() |
![]() |
#28 |
Registered User
Join Date: May 2016
Location: Henderson NC
Posts: 975
|
Re: 3:07 Rear End
I have a vortec 350 with a lot of low end torque with a th350 and a 307 rear. It works out great for me. Torque to get it going and gears for highway driving.
|
![]() |
![]() |
![]() |
#29 |
Registered User
Join Date: Sep 2011
Location: Ark City, Kansas
Posts: 3,339
|
Re: 3:07 Rear End
3.07 can work. Needs to be a V-8, preferably a 350 or larger. I drove my 67 Bel Air with a 283, TH350 lockup and 2.73 gear for 175,000 miles. I experimented for try for some fantastic MPG number. 20 MPG was all I got. If I were to do it over it would be a small block 400, TH350, maybe a 3.08 gear. screw the absolute MPG numbers. A heavy vehicle LIKE a pickup needs gearing to make things easier for the engine.
I'm not a proponent of O.D. transmissions. My 67 and 68 pickups will both have 3.73 gears when they get back on the road. I will compromise on the side of power the rest of my life. Needs to be at least a little fun to drive. My Bel Air ran great, just wasn't any kind of a powerhouse... |
![]() |
![]() |
![]() |
#30 |
Registered User
Join Date: Jun 2015
Location: Phoenix Az
Posts: 211
|
Re: 3:07 Rear End
My 383 runs great with a 700R4 very powerful truck
__________________
Brian Ritter |
![]() |
![]() |
![]() |
#31 |
Senior Member
![]() Join Date: Aug 2014
Location: Sandy, Oregon
Posts: 2,376
|
Re: 3:07 Rear End
Im in need of a set of 307 gears
![]()
__________________
My dad always says that HEI distributers are pointless... •1972 Custom/10 Deluxe. My first truck and I've had it since I was 7. Tilt, tach, AM/FM, 350, deep dish rally's, original paint and an increasing amount of NOS jewelry. It's always taking my money.. •1967 c10 with tach, dropped 3/5 on deep dish rally's •1972 Cheyenne Super. Sold |
![]() |
![]() |
![]() |
#32 |
Special Order
![]() ![]() Join Date: Nov 2004
Location: Mt Airy, MD
Posts: 85,858
|
Re: 3:07 Rear End
I guess I somehow got it reversed at some point. I could swear we went over this time and again and the correction was trucks were 3:08. I mean the threads from when Andy was here. He was the book smart knowledge and I was the knowledge from personal experience and conversing with the other 67-72 truck owners since new. And 3.08 was always the common knowledge reference, as I recall. I better stop recalling
![]()
__________________
"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) GMC '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 ~ 67ChevyRedneck ~ Grumpy Old Man ~ Last edited by special-K; 03-24-2018 at 07:03 AM. |
![]() |
![]() |
![]() |
#33 |
Registered User
Join Date: Aug 2006
Location: Redmond, WA
Posts: 6,332
|
Re: 3:07 Rear End
I'll tell you the ones I know, perhaps others can fill in the empty spaces:
GM 10-bolt car: 3.07 12/37 3.08333 GM 12-bolt car: 3.08 40/13 3.07692 GM 12-bolt trk: 3.08 40/13 3.07692 So that leads me to believe the cars and trucks are the same ratio, at least they have the same tooth count. I'm getting the truck numbers from this Yukon gearset for the GM12T-308: https://www.summitracing.com/parts/yga-24459
__________________
1970 GMC Sierra Grande Custom Camper - Built, not Bought 1969 Pontiac 2+2 427/390 4-speed Coupe 1969 Pontiac 2+2 427/390 4-speed Convertible |
![]() |
![]() |
![]() |
#34 |
Registered User
Join Date: May 2016
Location: Henderson NC
Posts: 975
|
Re: 3:07 Rear End
I have a 1970 TDE coded rear in my shop and it comes back to a 1970 3.07 open rear. Here's a thread talking about the same TDE coded rear.
http://67-72chevytrucks.com/vboard/s...d.php?t=578793 |
![]() |
![]() |
![]() |
#35 |
Registered User
Join Date: Nov 2014
Location: Lincoln City DE
Posts: 1,292
|
Re: 3:07 Rear End
Don't make a lot of dif [no pun] 308/307 , Only if counting to replace one or other,[ring or pin]......just get in the boat and row,no need to count the waves !
![]()
__________________
Stan 67 swb BLU MULE posted via flip-fone |
![]() |
![]() |
![]() |
#36 |
Senior Member
![]() Join Date: Feb 2010
Location: Falls City, Nebraska "100 Miles From Nowhere"
Posts: 2,219
|
Re: 3:07 Rear End
The 3:07 is a 3:08, just as the 3:08 in many cases is referred to as a 3:07. Car, truck, standard or automatic, it doesn't matter, they are the same. Davepl pretty well clears it up with the varying tooth counts, there is no such thing as an exact 3:07 or 3:08. I think the "three-o-eight" won notoriety because it's easier to say than "three-o-seven".
Tim is correct in that although the eight lug Dana 44's are referred to and matched with 4:11 Dana 60's or 4:11 14-bolts, it's actually a 4:09. No gear set is dead nuts, you can call it what you want, but the terminology will forever be a 3:08, it's just easier to say. Besides, a 307 is a motor not an axle. Harpo your correct in that it dont make a difference, and incorrect because you never change out just a ring gear or pinion. They are married sets lapped together from the foundry, when one goes the other must go with it. LockDoc is also correct in sharing his experience with OD transmissions, six cylinder motors and high geared axles. Cant compare a 5000 LB panel truck to a 3000 LB later model unibody. GM did not put 3:08 axles behind six cylinder trucks for obvious reasons.
__________________
Michael of the clan Hill, "Two Seventy Two's" 71 1-ton Dually 350 4-Speed 71 C/50 Grain Truck, 350 Split-Axle 4-Speed 02 3/4 ton Express 14 Indian Chief Vintage 1952 Ford 8N, "Only Ford Allowed On The Property" ![]() "Be American, Buy American" ![]() |
![]() |
![]() |
![]() |
#37 | |
Senior Member
![]() Join Date: Feb 2010
Location: Falls City, Nebraska "100 Miles From Nowhere"
Posts: 2,219
|
Re: 3:07 Rear End
Quote:
![]()
__________________
Michael of the clan Hill, "Two Seventy Two's" 71 1-ton Dually 350 4-Speed 71 C/50 Grain Truck, 350 Split-Axle 4-Speed 02 3/4 ton Express 14 Indian Chief Vintage 1952 Ford 8N, "Only Ford Allowed On The Property" ![]() "Be American, Buy American" ![]() |
|
![]() |
![]() |
![]() |
#38 |
Special Order
![]() ![]() Join Date: Nov 2004
Location: Mt Airy, MD
Posts: 85,858
|
Re: 3:07 Rear End
Corporate rears and Danas ran ratios right next door to each other. When I blew a ring & pinion in an HO52 I found there was a 4.56 and a 4.57 in the same year. The 4.57 GM listed as "non-Dana" and that was the ticket.
Like I said before, the ID tag on the front of my '72 K/20 Highlander read 4.09. The difference between that and the HO52's 4.10 doesn't make enough difference to matter and if it had a Dana 60 that would be 4.11. So the trucks care a lot less about this than we do ![]()
__________________
"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) GMC '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 ~ 67ChevyRedneck ~ Grumpy Old Man ~ |
![]() |
![]() |
![]() |
#39 | |
Senior Member
![]() Join Date: Feb 2010
Location: Falls City, Nebraska "100 Miles From Nowhere"
Posts: 2,219
|
Re: 3:07 Rear End
Quote:
![]()
__________________
Michael of the clan Hill, "Two Seventy Two's" 71 1-ton Dually 350 4-Speed 71 C/50 Grain Truck, 350 Split-Axle 4-Speed 02 3/4 ton Express 14 Indian Chief Vintage 1952 Ford 8N, "Only Ford Allowed On The Property" ![]() "Be American, Buy American" ![]() |
|
![]() |
![]() |
![]() |
#40 |
Registered User
Join Date: Aug 2015
Location: Alcoa;Tn
Posts: 208
|
Re: 3:07 Rear End
IMO you would be better off with your 3.73 gears and OD. My truck with 3.08 and 700r lugs the motor at 55mph.But it will run the speedo back to zero.According to the gear charts with 29 inch tall tires,3.08 gears.at 5500 RPM in OD you will be going 212MPH. I read this in a old Street Rodder mag years ago.
__________________
'71 Cheyenne Super LWB - Second Owner in 39 Years! '70 CST/10 SWB - Soon to be Daughter's truck when finished |
![]() |
![]() |
![]() |
#41 |
Registered User
Join Date: Jan 2016
Location: Barber City, CA
Posts: 4,787
|
Re: 3:07 Rear End
this thread made me chuckle so I'll toss this in for my contribution
![]() D60 4:10 LS FF GM truck 8 lug 41:10 = 4:10 ![]() ![]() I'm also considering a 200-4R upgrade, considering one of these from Art Carr here in town.. haven't had a chance to get over there yet, but I'll keep y'all posted if I find out anything of interest.. good luck!
__________________
I started out with nothing - and I still have most of it |
![]() |
![]() |
![]() |
#42 |
Special Order
![]() ![]() Join Date: Nov 2004
Location: Mt Airy, MD
Posts: 85,858
|
Re: 3:07 Rear End
^^^ That's just too simple. Please go away
![]()
__________________
"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) GMC '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 ~ 67ChevyRedneck ~ Grumpy Old Man ~ |
![]() |
![]() |
![]() |
#43 |
Registered User
Join Date: May 2011
Location: Northern Calif.
Posts: 3,700
|
Re: 3:07 Rear End
212 Yikes! This was scary enough!
|
![]() |
![]() |
![]() |
#44 |
Registered User
Join Date: May 2016
Location: Henderson NC
Posts: 975
|
Re: 3:07 Rear End
I understand that the actual gear ratio is not exactly 3.07. I was just saying it was listed as 3.07 on all the charts that I could find.
Doesn't make much difference either way though. |
![]() |
![]() |
![]() |
#45 |
Special Order
![]() ![]() Join Date: Nov 2004
Location: Mt Airy, MD
Posts: 85,858
|
Re: 3:07 Rear End
Just remember when you walk up the the parts counter to ask for a 3.07692 gear set for a GM truck 12-bolt and you should be fine (as long as they don't pull a car set)
__________________
"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) GMC '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 ~ 67ChevyRedneck ~ Grumpy Old Man ~ |
![]() |
![]() |
![]() |
#46 |
Registered User
Join Date: Jan 2016
Location: Barber City, CA
Posts: 4,787
|
Re: 3:07 Rear End
just pulling your chain special-K
![]() here's a couple of D44 tags with tooth count/ratio for reference.. note - the Dana advertised ratios are numerically accurate if rounding correctly ![]() '71 3/4t D44 front 45-11 = 4.09 [4.090] [D60 above replacing the HO52 rear of this rig ![]() ![]() '72 1/2t D44 front 43-14 = 3.07 [3.071] ![]()
__________________
I started out with nothing - and I still have most of it |
![]() |
![]() |
![]() |
#47 |
Registered User
Join Date: Jul 2015
Location: North East PA
Posts: 682
|
Re: 3:07 Rear End
What I am trying to Say ,the 200 4 r was used in many many configurations from the GM , my 200 4r came in the configuration that was mated to a 2.73 gear ratio so the trans I have was set up to shift to that gear ratio, this is why you will have conflicting results, you can to pull a 200 4r from the junk yard and just install it ,ibut needs to shift properly...A 3.73 ratio with a 2004r that was set up at Gm for a 3.23 ratio will not last long . its more about the the rear diff ratio then engine size.......
|
![]() |
![]() |
![]() |
Bookmarks |
|
|