Help picking gear ratio
 

Hey guys I need some help picking the right hear ratio for my car it's a 70 chevy nova with a sbc 355 with afr 215 heads 75cc chamber edelbrock roller cam .539/.540 lift 234/238 duration at .050
Single plane intake manifold professional products efi a gt45 turbo at 15-20psi b&m hole shot converter 3000 rpm in a turbo 350... Any help is appreciated

How tall is your tire??

It's a 295 50 15 =27inches tall

What will you be using the car for?

Traditionally, turbo cars do not like a ton of rear gear. I would say somewhere in the range of 3.55:1 - 3.31:1.

Not trying to one-up anybody but my old single axle med. duty dump truck has one of those 2 speed rears, Eaton, get this- 6.50-8.85!.. The spicer 5 speed is 1:1 in 5th!.. Of course 11r 22.5 truck tires, but wow does she have some gear..

On topic, I like a combo for the street that gets you right at 10:1 in first gear, all in, through the tires.

^^What he said!

It seems like the turbo like a little load put on it.

If you are racing then you need some tires first.The trans wont last long

As Autogear stated... I'd shoot for a 331 or 355 gear.

Larger diameter rear tires ( 29" slicks )
3.73:1 gears
Powerglide tranny.

:D

Currently there are 4.88 in it and I can just feel the engine running up in rpm to quick to make power... The gear I have doesn't allow much time in each gear and it pulls me out of my powerband

does it run ok with that cam?

It runs good I didn't wanna run a huge lift cam or a huge duration cuz I didn't want any piston to valve clearance issues

you have 4 degrees more duration on the exhaust side?you didnt say the LDA of the cam.If you have a turbo header with that cam? the duration is wrong way for split.
This engine should break the tires loose with 2.7 gears.how many cfm does your turbo charger system move?

I'm 23 and only been putting engines together for a few years so I'm kinda new to all the terms what is LDA? Do u mean LSA?