Well i've bought everything to do the vortec conversion but the intake. It looks like edelbrock and pro-products are the only choices. My question is what is best for me? I've read all the literature about the RPM range and selection but I've never come across a direct comparison on the same engine.

I have a 331 with a 216/228 0.545/0.480 112/107 Lunati cam that has a 1500-6000 rpm range. I run headers and a 4BBL with a 200-4R transmission and stock stall with 3.31 gears. It will be street driven and I don't expect to take it above 5500 RPM so the performer looks like it would be the best choice but most people are running the RPM or air-gap with the vortecs. What do you give up with the RPM/Air-gap on the low end?

Clyde

with your lower first gear in the over drive transmission, I doubt you'd be giving up anything on the bottom. My son runs the air gap on his 355 w/4.11 gears and it runs pretty good.

I don't think it's worth the money chosing the air-gap over the standard RPM. I have the air-gap myself, and it's a nice looking piece, but I don't think it out performs the standard RPM much, it a pain in the a$$ when it comes to hood clearance and tightening some bolts, and just isn't worth the extra cash.

i like the performer rpm....
shane

if your going to be running a cam that makes power up to 6K wouldn't it be wise to go with some lower gears, or possibly a higher intake manifold like the Victor JR?

a regular RPM with a valley/lifter shield,and block off your exhaust crossovers..same as an Airgap

On a dyno test of a Vortec 355" motor a Performer and RPM were tested. The Torque curves came together at 4600-4900. The Performer had the advantage under that, RPM over. Your engine being smaller would create this condition at about 350rpm higher, or 4900-5250.

I'd choose the Performer in you case.

I agree with Greybeard 100%. I used to run a vortec rpm on my truck, with a 600 edelbrock and later a 750 edelbrock. It ran pretty well, but I wanted more off idle torque, and switched to a vortec performer and a 650 holley spread bore. In my heavy 3.08 geared truck, the difference was night and day. I know the carb made some of the difference (especially on the lowend), but it pulls stronger from idle to 5K than it ever did before.