What is it thats different about the MPFI heads that helps performance on a non FI engine? Chambers, runners, valve size, all of the above, what?

TIA

------------------
Ya can't have too many fast Chevys!

 

i think it could be valve size.Im not really sure myself. I will soon see the difference on my project car

 

Valves; that's it. But it makes more sense to slap on a set of MPFI heads then to remove carb'd heads, port them, and put them back on... sort of like the same work with better results


------------------
-Tom P (Hot rodded 1986 Firebird 2.8l) from http://www.f-body.net/mailbag/3rd/3rd_mailbag.html message boards
---Think your car could be pic of the week? Visit http://www.f-body.net for details!

 

When ya do get your MPFI heads, have NEW valve guides installed.
Those wear out real quick.
Rest is just rebuild, properly (3-angle valve grind on the seats) get the heads planed (they tend to warp slightly!) and then slap them on.

IF YOUR BOTTOM END IS GOOD AND TIGHT
install a new timing chain and the MPFI cam from that same engine ya got the heads from.
Rest of your stuff, just rebuild.
I've done this (minus the cam) on my 1985 S-10 Blazer.
My short block is to far gone to have the cam benefit (OR to make the extra effort worth it!). When I get another V-6 engine, I'll do the MPFI cam trick OR it will already have the cam in it! My heads, carb and distriB. are all ready for another short block one day! All those parts are rebuilt by me! Next for that truck is a tranny, one day.

------------------
Chat Soon,
KED85
Karl
1985 Firebird 2.8 to 3.4 swap project for Smog Happy LA, CA