|
05-29-2018, 12:25 AM
|
#1 |
|
Registered User
Join Date: Aug 2012
Location: Grant NE
Posts: 78
|
Rear end
I bought a Eaton posi for my 3.25 rear end. I have a 700r4 transmission and so I I would like different gears. I thought I read when I bought it that the lowest gears I could put was a 3.42, but could I put 3.73s? I can currently go 100mph and I’m only pushing 2500 rpm, which is where my cam is just starting to be happy and I know if I can get lower gears I could get better fuel mileage. Currently getting 13.7mpg on the interstate at 80-85 mph. Or do you think 3.42 would be enough. I have a blueprint high performance 383 roller engine.
|
|
|
|
05-29-2018, 09:04 AM
|
#2 |
|
Registered User
Join Date: Nov 2011
Location: Williamsburg, VA
Posts: 956
|
Re: Rear end
I would go with 3.73’s personally, you’ll appreciate the low end power it will produce. If you don’t wanna go that low, I would then consider 3.55’s. That would be a happy medium of low end and freeway speeds with the 700R4.
|
|
|
|
|
05-29-2018, 10:26 AM
|
#3 |
|
Registered User
Join Date: Aug 2012
Location: Grant NE
Posts: 78
|
Re: Rear end
Will a 3.73 fit on my carrier?
|
|
|
|
|
05-29-2018, 09:57 PM
|
#4 |
|
Registered User
Join Date: Nov 2014
Location: Southwest Kansas
Posts: 306
|
Re: Rear end
You didn't mention what rear end you have , if it's a truck 12-bolt, then with 3.25 gears you would have a series-3 carrier. You can get "thick" 3:73 ring gears, that fit a series-3, you can also get 4:11, maybe even lower. I personally would go with 4:11's.
__________________
'64 C10 LWB, 283, 5speed '68 C20 LWB, 327, 4speed '69 C20 Custom Camper Longhorn, 350, 4speed '72 C20 Cheyenne Super, 396, TH400 '66 C60, 292, 4speed |
|
|
|
|
05-30-2018, 12:18 AM
|
#5 | |
|
Registered User
Join Date: Aug 2012
Location: Grant NE
Posts: 78
|
Quote:
|
|
|
|
|
|
05-30-2018, 12:23 AM
|
#6 |
|
Registered User
Join Date: Aug 2012
Location: Grant NE
Posts: 78
|
Re: Rear end
Sorry yes I have a 12 bolt. I don’t really want 4.11s it has enough power with my 3.25, 3.73 I feel would be plenty. I’m just wanting it to be a better cruiser on the highway and interstate.
Posted via Mobile Device |
|
|
|
|
05-30-2018, 12:41 AM
|
#7 |
|
Registered User
Join Date: Oct 2016
Location: Dallas Texas
Posts: 2,878
|
Re: Rear end
bbc=>700r4=>3.73 ( about +9 on the ODO here )
__________________
67 C10 fleet fuel injected '70 402, 700r4, 3.73 posi 07 335 sport turbo 6sp 94 Trans Am GT LT1 6sp posi -- sold after 22yrs 99 540 sport V8 6sp -- sold 73 240z L24 4sp -- given to friend 68 C10 step 350/350 3.73 open -- sold |
|
|
|
|
05-30-2018, 10:33 AM
|
#8 |
|
Registered User
Join Date: Aug 2014
Location: Alabama
Posts: 50
|
Re: Rear end
12 bolt truck carrier is 2.76-3.42 and 3.73 up. So you will have to do something different.
12 bolt car carrier brake is a total different animal. http://www.differentials.com/technic...arrier-breaks/
__________________
1972 C10 Cheyenne 402/TH350 1985 GMC 1500 Sierra Classic 350/700R 1986 K20 427/NV4500 1986 K20 Sub 406/TH400 "Life's tough.....It's enough tougher if your stupid." John Wayne |
|
|
|
|
05-30-2018, 11:11 PM
|
#9 |
|
Registered User
Join Date: Nov 2014
Location: Southwest Kansas
Posts: 306
|
Re: Rear end
__________________
'64 C10 LWB, 283, 5speed '68 C20 LWB, 327, 4speed '69 C20 Custom Camper Longhorn, 350, 4speed '72 C20 Cheyenne Super, 396, TH400 '66 C60, 292, 4speed |
|
|
|
 |
| Bookmarks |
|
|
Linear Mode
