I know a guy that is getting a DOHC motor built by Cobb and they are just amazed at the results of it compared to the previous results they've seen from SOHC buildups. Supposedly they just changed the intake cam, left the exhaust the same, and are pushing about 350hp to the wheels (yeah, nuts). My money is on the DOHC heads, but SOHC are good for lower money situations, I think.