So, replaced the head gaskets on my sons 89 S10 Blazer. I bought this thing for $500 and the guy told me it had been rebuilt. I did not mark the heads when I took them off but I did leave one of the studs in the one on the passenger side. So once I got them back from being pressure tested/ resurfaced I’d know which one is which.

I didn’t figure it out today until I went to bolt up the A/C compressor and bracket that the damn head is on the wrong side. (only has 2 bolt holes on the front of the head.) Of course I’ve already bolted the intake and exhaust manifolds on. I’ve seen some sites saying it didn’t matter which head is on which side but wouldn’t the blocked off port be incorrect along with the intake/exhaust ports? I really thought I was close to getting this thing back together now I’m gonna have to take it all back apart.

Is it possible that the wrong head was on the wrong side when THEY put it back together? Looking back at my pictures, I have the same head on the same side as when I took it off.

 

I have never seen a 4.3 with side specific heads. The ports match up on either side it is put on.