I haven't had time to read all the related threads, but I'm gonna throw this out anyway.

I hear mention of using 454 TB's. I'm a member of the NATC, which is dedicated to the 90-93 BB trucks. We have a member that bores and sleeves 454 TB's. The bore size is 56 mm and the throttle shaft is reduced to 4.8 mm. Go to www.454ss.com and look in the gallery section. Check out Jim Dickie's section. He gives a detailed explanation of this mod.

I am currently using one of these TB's on my truck and it is awesome! Jim can also modify intakes/adapters/spacers to use with the modified TB. Contact Jim for pricing.

I've also heard mentioned of higher flow injectors, but none of our members have been able to source any. Where are you getting these?

Bill

Wow, I'll bet the 56mm bores help out. My only question is what is used to funnel the bore width to the manifold? (I'll hit the web site next). I've had trouble getting a 52mm bore on the square form 4bbl manifold.

As for injectors the largest I know of are 90pph. Bumping the fuel pressure to 16-20psi will net a bit more flow.

My understanding is that there are larger injectors then these. They are for export vehicles running alcohol. I have not yet been able to verify this.

RBob.

I went there and searched all around and didn't find anything about a bored out TBI, or Jim Dickie, or anything of the sort

go here... bb tbi

man that thing is dope... It lookes like it would be a pita top get it to fit under the stock hood with a carb to tbi adapter, though... i want one. Shame it cant be used easily with the fuel injectors.

I must be blind. Thanks...note to self: do not surf the net at 8 am

With the MPFI on there why didn't the guy just buy a 4 bbl TB from Holley? He would've saved money and got 200 more cfm...

I'd like to see how much he spent on those heads.

Steve

Over $2K.

It can be used with stock injectors. In Jim's application, he has the velocity stacks installed because he has multipoint injection. I have one of his modified TB's and am using the stock injectors, FPR, etc.

Bill

I am currently using the Edel TB manifold with a 1" phenolic spacer. Both of these have been bored out to match the TB.

I am switching over the RPM Air Gap as soon as I get my heads finished. The TB will be mated to the intake with the Holley adapter (also bored out).

Bill