Avenger1970

I'm looking to swap engines as my current mill is coming up with just a tad less than desired compression (90-95lbs per cyl) and burning some oil.

Specifically I'm trying to find out what intake might be best for my build. Not sure what direction to go with this setup for the vortec heads.

I'm working with the following for my build:
350 2-bolt main bored .020 over
Vortec Heads #12558060 64cc (anticipated comp ratio about 9.5:1 - 10.0:1)
Full Roller Rockers 1.5 Ratio
Summit 1104 Hyd Flat Tap Cam 224/224 .465/.465 @.050
Hooker Comp Headers
2 1/2" True Dual Exhaust
Balanced Rotating Assym. (5.7 rods and 3.48 stroke)
Flat Top Pistons (Cast)
High Flow Water Pump
Direct Fit Radiator
Edelbrock Performer 750cfm carb


Looking for suggestions.

Thanks for the help

Bob Walker

Hi Avenger. I have just done a similar thing. Ended up with a Weiand Action Plus, but may change again in the near future. A couple of things to be wary of.
*Spreadbore or Square Bore? The Weiand is for Square Bore carbys, which is what I think your Performer 750 will be.
*What type choke? the 8121 won't accept EGR or hot air chokes. Your Performer is probably electric choke, so shouldn't be any problems. (except you might have to wire it)
*What height? This is the big one for 'Vettes. The Weiand is 3.375" rear and 4.5" front. It fits a C3 with aftermarket Air Cleaner and provides a bit of hood clearance.
*Port Size. The Weiand 8121 is quoted as 2" by 1.06". What size are the ports on your heads?

I'm thinking of removing the Weiand (although I haven't even fired the motor yet) and going for the GM Performance #12496820 Manifold. Why? Because it will accept a Spreadbore Carby (For many years I have been a Holley fan. I have now discovered the kick that a Quadrajet will give you when those huge secondaries open.) I just need to check the front & back heights. Hope this helps.

gingerbreadman1977

vortec performer rpm. your going to run an edelbrock carb so an airgap manifold will not fit under your hood. if you used a demon or holley 750 with a 3inch drop base air cleaner you would just sneak under, but no biggy because the performance difference between the two manifolds is minimal but airgap looks 1 HELL of alot cooler.

American Boy

Actually if you look at the Edelbrock site, the air gap manifold have the same carburator pad height. I'ts the bottom of the intake that is lower giving a wrong impression.

I ran my stock dual snorkel set up with a performer vortec intake (not the rpm). I had to lower the air cleaner by 1/8". The carburator height of that intake was 4.61". So any intake with 4.5" would fit with no modification. If you choose an aftermarket drop base air cleaner, then I think you won't have any issue with that.

The performer rpm could be a great choice for your set up with a square bore carb.

Here's a pic of my custom Super Victor intake with a Q-jet on top.

Stephan

BKbroiler

We don't know what year car you're talking about (avatar says 70, profile says 72 and 75). Hood clearance varies, more on the 75 than 70 or 72.
I have Vortec heads on my 77, with Edelbrock Performer, Qjet and drop base air cleaner. Fits easily, maybe even under the lower hoods.

OMF

Hi there, I would suggest the edelbrock performer rpm air gap. I used one of these on my stockcar, and was able to easily pull away from cars on a restart and ran it to about 7200 rpm. I was very happy with that manifold. I also just picked up the latest edition of "CHEVY hi-perfomance" magazine and they did a test on six or seven dual plane manifolds and the performer rpm air gap came out on top..........check it out.

jackson

Less expensive but dimensional & functional equivalent of EB vortec performer p/n 2116 is:

Professional Products vortec cyclone p/n 52007 (satin), or 52006 (polished) ... fits spreadbore & squarebore ... NO EGR ... dualplane lowrise.

Avenger1970

Hey everyone!

I apologize for the delayed reply here. It's been a crazy time these past couple years! Finally getting settled down and back to the Vette after dealing with a lot of real life issues.

I would like to say that I do and did appreciate the information given here from everyone! I wanted to follow up and post the final build on my engine. It's finally together and will throw it in as soon as I get my tele-tilt, pwr steering in and engine compartment completed.

Not much actually changed with the build and no still haven't yet fired it but hoping it will be a runner.......and ALL for WELL UNDER $1000.

Decided on a Performer RPM Vortec Intake

1972 Corvette
350 2-Bolt Main Bored .020 over
Balanced rotating assembly 5.7 Rods, 3.48 Stroke
Cast Flat Top Pistons
Edelbrock Performer RPM Vortec Intake
Cast Iron Vortec Heads 1.94 / 1.50 Valves 64cc combustion chamber
Head Gasket Fel-Pro, Comp Thickness .039
Aluminum Full Roller rockers 1.50 ratio
Hyd Flat Tappet
Comp Cam 12-238-2 / CS XE262H-10
(@.050 218int 224 exh) (Lobe Sep 110.0) (Lift .462int .469exh)
High volume oil pump (Blue printed)
High Flow Water Pump with DeWitt Alum Radiator Electric Fan
Hooker Comp Headers Ceramic Coated
2 1/2" Dual Exhaust
Edelbrock Performer 750cfm carb (Looking for a Demon in the future!)
TH400 Transmission / 1900 RPM stall (?)
3.08 gears

Hoping to get at least 9.5:1 compression out of this and keep it under 10:1. Not sure what the power numbers will come in at but believe they will be respectable.

Wasn't planning a high spinning motor.....nothing above 5500rpm and planning to shift at 5000rpm.

Again, I appreciate the input from everyone.

Added Photos: (Had to test posting pictures too!)

Avenger1970

Here's my project......not a numbers car or correct anything it seems. Just going to be a driver.