macmatt

Hey Everyone. I'm new here. I have owned several third gens in my life but I've been out of the hobby for a few years. A couple days ago I bought a 91 firebird w/305 TBI 700r4 trans. The car needs a cylinder head. My question is this...What cylinder heads will work on this engine and how can I identify them (in a junk yard for example)? I am not opposed to replacing both heads of course, since you never know what may be wrong with the other one. Any advice you can give would be much appreciated. Thanks!

Damon

Just about any 305 TBI engine from the mid 80s through the early 90s will interchange (car or truck, as long as it's TBI and off a 305). Their casting numbers end in 187. Nothing else is a direct interchange. Fortunately, they made a bezillion of them. The 305 TBI engine was the "base model" V8 workhorse engine in almost every fullsize RWD GM car and truck from 87 through 92. As well as the entry-level V8 in RWD cars like the Camaro and Firebird in those years.

TNT_Z28

any sbc heads '87-'95 should have the same intake bolt pattern (or angle, whatever the technical differnce is) so keep an eye out for centerbolt valve covers (easy way to identify them)

check casting numbers for confermation

stick with 305 heads. ones off a 350 will have a bigger cc combustion chamber, thus droping your compression ratio.

also, it would be a good idea to have your replacement heads (or head i guess) tested for cracks and remachined/redecked. it sucks to do all that work just to redo it all over again. been there...

and please, please, whatever you do, buy a new set of head bolts for each head you decide to replace. ive laughed at a couple of friends that didnt take that advice and ended up having more head issue within the month of there overhaul.

macmatt

Thanks. That will help tremendously.

TNT_Z28 that's good advice. I had considered what you suggested and it depends on the cost. I was merely looking for something temporary so the car can be used until I have the engine I want ready for the car. It has a blown head gasket(s) on the DS currently and the only reason I'm replacing the head is because it has a stripped spark plug hole on cyl 5. Of course I would have the head checked before I put it on regardless. Speaking of engines, would there be much to putting in an engine from a corvette around the same model year? That's what I've been looking into doing. Thanks Again.

macmatt

and of course New head bolts. An ounce of prevention and all