Who makes the aftermarket throttle bodies that you use when you have the injector bungs welded into your carb'ed intake to convert to EFI???

I'm thinking of switching to a MPFI setup but I dont want to use a GM TBI's that have the injectors mounted in them.I've seen a Holley 1000cfm for about $650, but I'm not gonna need anything that big....................

Oh yeah, I'm on a budget (hahaha), so the cheaper the better...

I dont think throttle bodies are rated the same as carbs you probably wont find any thing like a 750 cfm because the throttle body doesnt need to atomize fuel there fore there made larger than carb bodies with less enphasis on fuel atomization and venturi afects.

You can use a 4 barrel carb and just use the bottom part. Put you have to use TPS. So build a cheap system can be done. Otherwise i know peaople using twin 60mm Audi A6 bodies.

Here's a good source:

Force Fuel Injection (http://www.force-efi.com/)

The 1000 cfm throttle body will work fine. Check Ebay also. I just saw a brand new 1000 cfm throttle body for sale.

Dumb question maybe . . . but what IF you used a vac secondary carb like a Holley O-3310 as a metering plate on a SFI system?

Just take out the venturis and smooth the bores. Then put a light secondary spring in the vac can and go with it. It would have the nice progressive vac secondary action keeping velocity up there through the entire RPM band.

Best of all -- without venturi the O-3310 would probably flow close to 1000 cfm . . .

Eric68 or others: If you do decide to use a carb and you remove the venturies, do you need to plug any passages or anything,or do all the circuits just become air circuits?????

The most difficult things about using a carb for a throttle body is the fact you need a TPS and IAC.

On my first MPFI years ago I used a Qjet for an air valve. I added a TPS and an IAC to it.

You can use the FAST or BDS remote mount IAC. You can make your own remote mount TPS also.

I wouldn't mess with anything vacuum. With EFI you can mash it with a super tight converter and a big cam and get no hesitation if it is tuned right.

Yeah, good point Doug -- seems like a vac secondary carb as an air valve would make it hard to program the computer to match consistently.

Doug F.- you have mail.......