7t9l82

just a comment, most people chose a vacuum secondary carburetor to go with an automatic transmission because its easier for most people to tune. i run a double pumper with an automatic because it is more responsive. some people claim that a double pumper carb makes the car feel faster than it was thus feeling it must make more power. people like Lars say the horsepower is the same, i contend that it is the quicker response they feel and not a power advantage. i also agree that too big a vacuum secondary carb basically is not an issue. i have run them all, all have merits .

johnt365

You don't mention what the primary goal is for the car, racing or cruising.

What is the average rpm range you will drive the car in most of the time? Mathematically, most calculators that I've seen show a 600 as a good choice for a 350.

I have a 350 with automatic and have run both a Holley 600 vac sec and a Qjet 750. Since you already have a rebuildable carb I would make sure and consider the pros and cons of each brands design.

A few threads over Lars outlines a common hot start problem with Holleys due to the bowls hanging over the intake and fuel boiling out the accelerator pump. http://forums.corvetteforum.com/c3-t...post1587158286

For the street, I really enjoy the Quadrajet design with the APT screw for part throttle tuning. This design makes it possible to get excellent power during hard acceleration and still really fine tune for efficiency while on the hwy cruising.

If we were sitting around drinking beer, I would probably try to talk you into rebuilding your current carb. If I needed a new carb, I would probably look for a Quickfuel or Holley that will allow you to tune the part throttle circuit.

Haggisbash

I would second the Quickfuel choice, have a look at the BD-1957 model.

wilcar

Keep the 600 carb and rejet and change metering rods. I run a 600 1405 edel on my 84 c4 with 9.3 c.r. large valve summit/dart cast heads with a 228-228 @ 050 solid cam. I am running .095 primary and secondary jets and 068x042 rods which is about 3 stages lean based on edelbrock tuning chart for the 1405. Have plenty of power but I use my C4 for street driving and rarely go over 5000 rpm. Run a 1/2" composite spacer to prevent fuel perc. For street driving I could probably use a 500 cfm carb and be fine.

peterbuchberg

I have no hood clearence for a 1/2" spacer. Maybe an aluminum heat shield will do the job

scottyp99

Have you actually measured your clearance, or just estimating?

Scott

peterbuchberg

I'm running the stock air cleaner, but modyfied to fit the edelbrock carburator and the height off the EPS intake. So I know.

scottyp99

So how much clearance do you have to work with?

Scott

peterbuchberg

Maybee 1/8 " it's real tight.