I've got a performer spread bore intake on my small block and a square bore Holley I want to try on it. It bolts up and the throttle blades clear.......to me it looks like it would work.
I've also have the spread bore adapter that mates a square bore to a spread bore but I don't have the hood clearance to run it. Is anybody tried running a square bore on a spread bore intake? Successfully?
Roger

The Edelbrock Performet intake is designed both types of carbs. Just make sure you don't have a vacuum leak at the base, and you'l be fine.

You can buy an adapter plate that fits under the carb, like the $5.95 Edelbrock 2732 from Summit. This will cover the wide area at rear barrels and prevent vacuum leaks.

http://store.summitracing.com/partdetail.asp?part=EDL-2732&N=120%20300507

You need an adaptor plate to use square bore carb on spread bore intake.

Originally posted by ZZ69chevelle:
The Edelbrock Performet intake is designed both types of carbs. Just make sure you don't have a vacuum leak at the base, and you'l be fine. Bingo.. the performer manifold (not the RPM) is designed for both square bore and spread bore carbs.

If the manifold you have is the performer, the performer vortec, or the performer air-gap and not RPM, then you won't need any adapter plate. If it IS the RPM, you will need an adapter plate.

EDIT: The RPM Q-Jet also accepts both square and sread bore carbs.

I'm running a square bore on a spread bore style intake on two of my V8's and have no problems. Just make sure you got a good seal around the carb base.

Thanks for the info guys. It looked like it would work. Roger

When I ran a square bore carb on a Performer, I had to use the Edelbrock plate. Not the big, thick spacer/adapter, just the little 3/32" plate with two gaskets. I doubt your hood clearance is that tight.

I mention this "just in case".

Just my 2 cents.....I have a square bore Holley sitting on top of a Weiand 8004 intake which accepts both types of carbs and is similar to the 2101 performer intake. I only used the wide gasket (provided with the carb) when I put mine on....no spacer or adapter or anything. To my knowledge I have no vacuum leaks. Not saying this is the right way or that it will work for everyone....just my experience. Probably better to go with an adapter anyways. ;)

I've had my 625 demon on my performer for 1 1/2 years daily driven.

Use the #2732 Edelbrock plate. It's very thin and give support at the rear of the carb to ensure there's no leaks. Yes, it can work without it, but I've seen enough that didn't seal to advise you to use it.

Jody