As some of you know i'm looking at head work etc....
Just wanted to know if a S1 head will bolt straight on in place of a S2 head i know it will on the block it was the inlet manifold i wasnt sure about as the S1 is different to the S2, will they match up? I also noticed the exhaust ports are round on a S1 head and squarer on a S2.
All the vavles etc will be replaced so it's is just a bare head comparison really.

Thanks!