swapping gears

[vanman86]

im buildin up a 86 chevy van with a 350 bored .40. lunati voodoo series mild cam, headman headers and a turbo 400 trans. its tbi. just wondering what kind of gears i should run. right now it has 3.08 and i deffinatly wanna change that. i was thinking 3.55 or 3.73s any advice?

[Lash]

What it's primary use going to be?

[wrath]

What size rubber?

I believe the vans were only available with 305TBI and 4.3LTBI engines in 86, so are you building a half ton van or a 1 ton van?

[70 cutlass 442]

that trans will eat up some HP versus a TH350... it really does depend on the use. the 3.73s would probably... but you really need to match the cam, tq converter, gears, tire size, and vehicle weight to get the best performance. So that beigne said, wich cam are you looking at? whats the compression ratio, and what stall converter do you have?

[Prince Valiant]

You'd be surprised that even in a heavy vehicle, how well a mild cammed small block will perform, even with mild gears. I recommend holding off until you get the engine done up, and seeing how it performs. If you're dead set on a gear swap, might as well go with the 3.73's.

[juicedimpss]

if you can fit a 31" tire,id run a 4.56

[GTO RLY?]

Yah, go with 4.10's. I had a '79 E-250 with a 460 & C6 that would roast tires just mashing on the gas. Plus I could tow like 11,000 pounds. :D

[BAD LS1]

Gotta be good for it wingining away at 3k+ RPM on the highway with anything over the 3.08's....

[Dr.Buick]

5:13 and launch the tires off the ground off the lights:rolf


3:73 will be good at freeway speeds should be 2800 with a 28 inch tall tire

[vanman86]

ok its an 86 half ton van. it was carbed but now someone made it tbi 4.3 so im keeping it tbi. im not sure what cam it is exactly but i can look at the specs and let u know later. as far as the tq im gunna run the stock one. i kno how tough th400 r even when stock, prolly will rebuild it sometime down the road. i plan for it to be a daily driver during the summer. the occational hwy 100 run to smoke some turbo desiels maybe :). i want some kick to her but i dont wanna lose any top end cuz itll be doing some hwy travel too. i kno the 3.08s r better for the th400 and freeway driving but idc if i sit at 3 grand doing 65 or w/e. i know the th400 eats like 30 hp but id rather that happen the blow a th350 or ever a 700r4

[vanman86]

oh i have 225/75/r15 tires right now thinking about 235 soon. my spedo already screwed up anyways so idc anymore about final drive lol