When I was looking for pistons for my 153 I ended with a few sets. None had the advertised pin height. It seems that in order to control compression in bored engines the manufacturer reduces pin height. So the 307s should have been zero deck for me but weren't. I did get a set of 307s with only 2 valve cuts.
The ones Vman got are better than most because they don't have the chamfer around the top and the D does look shallower. The price was right. So if he is looking for some low buck improvements for a mild engine all he needs is a 194 head.
