can i use pre 87 heads on a 87 engine? if so is there anything i need to modify because it seems like there is more choices for the older heads.
thanks.

 

Yes, just watch the size of the ports (In and Ex) and the size of the combustion chambers so you won't lose combustion ratio.

Jake

 

A block doesn't care what heads are on it, except for chamber size. The problem is when you try to fit a center bolt pattern intake on a perimeter bolt pattern head, or vice versa. Nothing that can't be handled, just needs to be addressed.

 

The listings you are looking at ,are intended as exact stock replacements so the only difference as noted above is the centerbolt covers or in the case of late F-body cast heads the different intake bolt angle.

 

It appears you over-stated your position. Let's not forget about LTx, LSx blocks, etc. "A block . . ." includes those as well. Replacing the "A block doesn't care . . ." with "Your block doesn't care . . ." would be more accurate; avoids confusion.

OP, what specific heads are you looking at? I don't see them listed in your post. Listing "pre 87 heads" can be tricky because "Y" body 86 Vettes (and perhaps other bodies as well) can with come either parameter or center-bolt heads, calling for different valve covers.

Failing to consider post size can have a negative impact on intake manifold port matching and, if they are significantly larger than the stock ones, will effect drive-ability.

Seems you're considering what, to most of us, is a significant amount of money, so it's best to be detailed. It's always best to be as specific as you can and provide as much detailed information as you can. Doing that helps avoid mis-information from being suggested.

Jake

 

i was just going to pick up a used set on ebay or craigslist because i have an intake and valve covers that will work on the parimiter bold heads.

 

I didn't want to write up a 3-page detailed report on the difference between small blocks vs big blocks vs LT1 vs Vortechs vs LS1s (which have NOTHING in common with Gen 1 blocks).

 

also, is there a way to do a compression check with the motor all apart. the heads are still on.