Are 86na and 87na heads interchangeable?
 

My 87na blew a head gasket today and overheated etc. I've got an 86 parts car that has an intact engine. Are these heads the same? Looked on Courtesy site and they have two listings - one for 84-89 and another for 87-89... Any help?

Are the W heads stamped for identification?
 

Thanks AZ Bum - just what I needed. Are the heads stamped so I can confirm which heads I have and need? If stamped - where should I look?

Look at the coolant passages. The "W" series heads are slightly different in their locations. It will be obvious when you hold them side by side. Since you have the A/B block, you're going to need the A/B gaskets regardless. So you should be able to hold the head gaskets up to the new heads and see if they line up right.

Can you tell difference in heads without pulling from block?
 

Wish it was as easy as setting them side by side... Wife blew up the car 500 miles away, its sitting at a repair shop. My 86 is at home and not disassembled - so before I go through the effort of tearing down the 86 motor I'd like to find out which heads I have...

If I understand, looking on the 87 "major engine components" will show a "W" stamp to identify the W engine - but the block itself is not stamped. I'm just wondering if there is some external identifier on the engine assembly that would tell me for sure the 87 is a W.

The 86 would for sure be an A/B head, and according to the link info table, I CAN put a "former" A/B head and gasket on a "modified" W block - right?

Is there a down side to this combination, and should I try to find a W head assembly instead?

Sorry for the interrogation - just want to get this right especially since I don't know the mechanic that might work on the car.

Thanks

The block on the 87 will identify which motor it is.
Your 86 will be A/B unless it's been replaced. The ID number on the engine will say if it's an A/B or W series motor.