Does anyone know off hand how close these heads are? I just ported a DSM head for a friend and got 32.55 cfm increase with stock valves. My friend said that ties the most gain from a stock head. If they are similar I might do some more and use one and make a 2.2block with 2.4 head.

 

I'm not sure how close the heads are but if you want to run a 2.4L head on your 2.2 Indy sells a 2.4 head ported and polished for $600, plus has a 3 angle valve job, and the heads have been checked for cracks and warpping.