i wasnt sure which section to put this in so general engine seemed good. i wannna put a set of vortec heads on the 305tbi in my 91 firebird and i found a listing on ebay with rebuilt vortec heads , http://cgi.ebay.com/ebaymotors/GM-30...#ht_500wt_1118 , but in the listing he asks to pick wich model and there is more than one 305/5.0l so which one do i choose? also the engine in there is not the original it is from a 91 buick roadmaster, does this make a difference? any help would be appreciated

 

To use Vortecs, you're going to need them milled for compression.
I believe your LO3 is basically identical to all the '88-'92 LO3 F-cars.

 

You are aware you also need a special Vortec only intake to bolt up to the new heads?

 

Those are 059, the 305 "Vortec" head; not, actual "Vortec" heads.

CHevy has discovered people like tha tword, and has been slapping it on basically EVERYTHING they make, just because .... people like the word.

In other words, when applied to ANYTHING besides 0062 or 906 castings, it's just a BUZZWORD.

AFAIK the only thing those heads have in common with actual "Vortec" heads, is that they have the same bolt pattern so that they can accomodate the CPFI system.

Meaning, you'll get basically old-school results, not "Vortec", but you'll have to pay for a "Vortec" intake.

I suggest re-thinking this plan.

 

lol only thing youll get is center bolt valve covers that are easier to seal

 

"Vortec is a trademarked name for a line of piston engines for General Motors trucks. The name first appeared in 1988 on a 4.3 L V6 that used "vortex technology" to create a vortex inside the combustion chamber, creating a better air/fuel mix.
Now its used on a wide range of different GM truck engines."

 

i see, so this isnt a good choice then. i guess i'll have to keep looking for something else maybe if i can find regular aftermarket performance heads. thanks for the help