What's your thoughts on the $100 ProForm Holley main body that Summit and Jegs sell ? I've always wanted a carb without the choke horn, plus the polished look would be awesome. Anybody using it ?

 

My friend first cut off the choke horn on his Holley and smoothed off the edges. He gained 1 tenth at the track. He put the Proform main body on it and gained another 1 tenth. I think its definately worth the money

 

That's pretty damn good. Better performance AND better looks!

Will this work with a double pumper type carb ?... they dont mention that in the ads.

 

wait u have a 412 behind a world class t-5??? i am puttin it behind my mild 350 how do u think i will do? thanks

 

Notice the N in front of it ? That's a NON world class. It's holding up well. It's ALL in how you drive it! Drop the clutch at 5000 rpm (thinking you're actually gonna get any traction) or powershift it and it'll go out even behind a V6.

 

They have one for DP and one for VS.

 

I'm using a 750VS and I bought the proform carb base because it seemed like a perfect match for my car. The choke tower on my original carb body came very close to the air cleaner lid which, no doubt, was a restriction.

The first thing I noticed when I opened it was the sticky coating so make sure to have some carb cleaner on hand. I also noticed it was deburred fairly well except for a couple threaded holes on the bottom. The entry to the venturis is very smooth too and the bore size and position matched perfect with my throttle plate. It appears they did a good job with this peice even though, on the packaging, is a little blurb that reads "Swap it in, swap it out" which sounded a little ominous to me. I've had experience with a Proform HEI (It was on the car when I bought it) that left me stranded twice.

The test assembly went well until I placed the rear float bowl in place and found it would not seat. I had to file down the top of the aluminum around the PCV port on the throttle plate and then everything snugged right up. I'm using a secondary metering block with jets so the extra length could have been the problem. No biggie though, I have plenty of files.

After re-installing and filling the float bowls the car fired right up. No leaks at all which I was glad to see. The car was running a bit lean though. About two steps up from the stock base sounds about right but I had my car dyno tuned and they drilled the jets so I'm not sure exactly how far they wen't.

The only real problem I had was getting the secondaries to work right. On the dyno, which is a third gear roll on, the secondaries seemed to open fine. On the street, however, they wouldn't open at all in first, barely tickle in second and then pull like a MF in third. With the check ball removed from the secondary housing they would just snap open and I had a bad bog. Stiffer springs only delayed the opening point, they would still snap open and produce a bog.

The solution for me was a Quick-Fuel adjustable secondary housing that has a needle valve to adjust the secondary opening rate. Let me tell you this sucker works. I set it up per the instructions and now I have all my power in any gear. I would recomend you get one while you are at it as they are only $35.00 or so and are a perfect match for the carb body. Throw in some Moroso reuseable rubber gaskets and you'll be set.

Overall I would say I gained at least 20 HP and much better engine response over the original base. Well worth the money and effort. Price a new HP carb with milled choke tower and see how much you save by using the Proform body.

One more thing, I thought this was funny, there is a large chrome plated plate on the drivers side of the carb body. This is not visible in any of the pictures I've seen of the carb body. It has a big Proform logo and a warning that says "DO NOT REMOVE THIS PLATE". Well, of course I removed it without a problem.

Anyway, I hope this helps!

Andy

 

 

Looking good... looking good! I thought they were chrome for some reason though ? I guess not. Or maybe the chrome version is more expensive ?

 

Here's the DP version. I had to file down the PCV port boss on the throttle body as well - must be a Proform dimensional "error". The riveted name plate apparently is gone. I hadn't heard anything about needing a larger air cleaner stud, had to fabricate one.

I have a little tuning to do - part-throttle surge. Since I'm at altitude, I dropped down 4 jet sizes from their recommendations, might have been too much. I'll try going up 2 and see what happens.

Quantified performance results coming tonight.

 

Anyone know where I can get a new baseplate? The shafts on mine are leaking, and I don't really want to mess with installing new bushings. Does Proform have these, or anyone for that matter?

 

Proform #67155 for 650 to 800 DP'ers