You'll find the casting # on rocker arm/valve spring side of the head, it should end in "884" on both the 2.8 and 3.4 heads. There were some other casting #'s used but the most common are the "884" heads; all have larger valves than the older heads used in carb'd versions of the 2.8.

At any rate, you should be able to use the cast-iron heads from any '86-up GM injected 60-deg V6.

Too bad we can't bolt up a TBI intake to the FWD aluminum heads, used with the right pistons they'd be quite a performance boost.

Maybe we need a a-dap-tor kit!!!! <img src="/forums/images/graemlins/notooth.gif" alt="" />

Anybody up for an MPFI alum head swap???