I am asking this question for a friend he has an 86GT and wants to do some aftermarket heads, he knows the choices are limited due to the flat top pistons, is there a list of aftermarket heads that will work with a stock 86gt motor? I know someone must know. Thanks for any help.
They make a tool to notch valve reliefs in the pistons, supposedly easy to do with them still in the block, just take the head off and use the tool. I don't know the specifics but someone told me when I was looking into an 86 gt. And its all about clearance. It also depends on what cam is being used and heads combination.
I don't know what heads, but i'm betting you won't even get away with GT40s, which are pretty mild compared to even the mildest aftermarket head. The problem as stated above is valve clearance, which the '86s have none. The reality is that if he's got the cash for new heads, he might just wanna save up and buy a used '87+ roller block and swap everything over.