Author Topic: Need some rear end advice  (Read 2043 times)

Offline qmr55

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Need some rear end advice
« on: March 26, 2015, 06:32:55 pm »
Ok so my build is an 85c10 lwb. was originally a 305 w/700r4 4 spd.

swapped in a built 350 from a chevelle .60 over, mild thumper cam, edelbrock alum intake, 72 cc alum heads,  4 bbl carb, long tube headers and 2.5" custom exhaust....

still doesn't have tranny to rear setup in it.

thinking a second gen bw super t10 or an earlier muncie, suggestions?

next, what rear end should i run? i dont remember if the stock is a limited slip or not, if its not, what should i put in it?

its not gonna make a ton of power so i believe the stock will hold up fine but if its not a limited slip i dont want it.

looking for any suggestions! thanks guys

Offline zieg85

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Re: Need some rear end advice
« Reply #1 on: March 26, 2015, 09:40:01 pm »
Things to consider:
*The cam description is vague and most thumper cams sound good but lack performance on the lower rpms.
*Even a 1/2T weighs a chunk so you are going to need a decent gear to get it moving
*search the gear ratio's and pay attention to first gear.  Old muncie 4 speed, the earliest first gear was 2.56 M20 and the M21 was 2.20
*your 700R4 is a 3.06 or so plus being an automatic has some torque converter slippage and most likely will have a 2.73 gear in back. 
*you'll want to pair the trans/rear end gear to the engine cam so you don't have to slip the clutch to much to get the truck rolling.
*if you do any highway driving you also don't want to go too low in gear or the engine will be pulling high rpm's in 4th.

You will want to weigh this out carefully because the truck, even though it will sound good may be a real dog if not geared right or only be an around town truck with no highway manners. 
Carl 
1985 C20 Scottsdale 7.4L 4 speed 3.21
1986 C10 under construction
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Offline roundhouse

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Need some rear end advice
« Reply #2 on: March 26, 2015, 09:56:57 pm »
The  NV 3500 would be nice
4.0 to 1 first gear and OD

I'd look for a 5 speed OD and Decide with size tires you're gonna want to run and select the axle ratio based on that

I didn't know you could go .060 over
You got any cylinder wall left ?
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