Can someone tell me when in the production run the change was made from cast iron to aluminum cylinder heads?  I'm pretty sure mine was fairly late in the run but would like to know for sure.  The last 5 numbers are 19445 if that helps.

Thanks,
Lenny

Hi Lenny. I don't know when exactly in the production run, but I can give you an easy way to tell. If you have center bolt valve covers, then you have aluminum heads. If you have bolts on the outer edges of the valve covers, then you have the cast iron heads.

They did have issues with cracks around the head bolt bosses, so the heads were delayed. ALL convertibles did come with the aluminuminum heads, and the LATE coupes. I'm not sure when the exact date was, either. And..if counting the bolts that hold the valve covers on is too hard, just stick a magnet on 'em...

Thanks guys.  It has the bolts in the center of the valve covers so I guess that means it has aluminum heads.

Nope...not until '86, and then only after they got the broken bolt bosses figured out. By the time they did that, they were also ready to start building the convertibles, so all of the convertibles had the alum heads. I'm sure there is specific info somewhere on the VIN/date break.