Hi, I was just looking for some suggestions on what I can do to make my truck faster, it's pretty fast but seems like it could be a lot faster. it is a 400 with the following mods:
Edelbrock performer carb (600 cfm)
Edelbrock performer intake
carb spacer
headers
duel exhaust
double roller timing chain with timing set to 0
unknown cam (not stock)
Mallory unilite hei distributor
C6 with shift kit and 2,500 stall torque converter

I don't know what gears it has in the rear, but if I change them won't I lose top end power?

What if I put a higher cfm carburetor on it?

thanks in advance!

Carb is big enough. What gears are in it now and what tire size?
You can run numbers with this calculator to see what different ratios will do, a deeper gear will get you going quicker but can limit your top end depending on what it is.

http://www.csgnetwork.com/multirpmcalc.html

Sounds like you have done what you can do without pulling it and doing a complete rebuild..I assume the compression is good?

Higher gears would increase the top speed, lower gears will decrease top speed and increase acceleration

I don't know what gears it has, how do I find out? Tires are stock size I think, I will check tomorrow. I have never done a compression test but it should be good as the motor has low mileage since it was rebuilt.

I'm thinking some kind of high ram air intake with a bird catcher but I can't find any...

Increase the dimensions of the engine and add 60+ cubes...

Not much can be done with a 400, so to speak. Tunnel ram will kill almost all bottom end, you'll most likely need major internal mods, ported and polished aftermarket heads/intake, etc etc... Gonna get spendy....

Gears are probably either 3.55s or 3.73s, door or axle tag will tell you.

1970Custom said:

Increase the dimensions of the engine and add 60+ cubes...

Not much can be done with a 400, so to speak. Tunnel ram will kill almost all bottom end, you'll most likely need major internal mods, ported and polished aftermarket heads/intake, etc etc... Gonna get spendy....

Gears are probably either 3.55s or 3.73s, door or axle tag will tell you.

Click to expand...

Bummer.. I'll check the axle tag tomorrow, door tag is from a different truck.

Another way to check the ratio is get one tire in the air, mark the pinion and the tire and count how many times the pinion spins vs the tire, not exact but it'll be pretty close. 3 1/2ish revolutions and its 3.55s 3 3/4 revolutions and its probably 3.73s, etc....

1970Custom said:

Another way to check the ratio is get one tire in the air, mark the pinion and the tire and count how many times the pinion spins vs the tire, not exact but it'll be pretty close. 3 1/2ish revolutions and its 3.55s 3 3/4 revolutions and its probably 3.73s, etc....

Click to expand...

good to know, I don't think it has the axle tag anymore. what is the pinion though?

yank that boat anchor out then we'll talk lol..

camshaft, ignition parts roller rockers, etc.. small stuff until get spendy..