Has anybody used the stock, 42mm (or an enlarged 46mm) GM TBI unit on a Holley "Pro-Jection" TBI manifold with 2" bores? If so, what were your results? If you know someone that did, and have a link, please share, I couldn't find anything.

I found a thread in this forum relating to this, but they found another way to solve their problem, thus the question went unanswered.

I want to use aluminum heads with the old 86-earlier style intake holes with TBI. These ProComps seem plentiful and cheap:

http://cgi.ebay.com/ebaymotors/350-3...Q5fAccessories

I would use a small cam, something between a RamJet cam and a 1705 LT1 cam. These heads are less than $700, and would support plenty more power if I wanted to change cams later.

I am considering drilling the stock manifold or using a single plane manifold that would fit these heads and getting a carb adapter. I'd prefer to have a place for the EGR valve (for visual inspections), even though I don't think the ProComps have EGR crossover, but I acknowledge the gains some have had with single plane manifolds.

 

I run the GM 7.4L TBI unit with that Holley manifold. Seems OK for me.

Those heads may be too large at 215 cc. Would require a much larger cam than you are suggesting. 170cc-180cc may be a better choice. Does the seller offer smaller?

Has anyone had success or opinions with ProComp? Who are they and what are they called now?

For a single plane carb manifold a Weiand Accellerator is a good choice.

 

Thanks for the input. I did see that they offered a 190cc version of that procomp head, but probably still a little large. They must be plentiful and cheap for a reason, right? So, maybe not the best head. I was also looking into some ZZ4 heads, but may just pony up the dough for the stupid GMPP Vortec intake. I've got modest ambitions, as implied with my cam selection.

 

If I was looking for low cost and value I would consider Summit brand of alum heads.