The unported heads will work OK on a 4.1. The ports are rather small in their original configuration. no stock block will accommodate the extra head bolts......no material in the needed locations.
You will find that the springs you have selected will be inadequate to control the valves at higher RPM (above 5000). I have been through this exercise before. S2 heads require alot more spring pressure even with mild cams
If you are looking for S2 valvetrain components send me a PM. I have LOTS of rockers, springs, pushrods etc for S2 engines.
And a curious exercise it is.
So was it just that?....An exercise? What did you do for headers? Intake? General fitment issues for all types of other things?
I know you can use stage heads on any production block. And I certainly would use a set of stage heads to bolt to a production block if I wanted to mock up fabrication for an Off-Center Stage Motor that was being built for me somewhere else for a later time.
However, It doesn't seem to make sense to permanently add this complexity to a combination that will make anything less than a thousand horsepower.
Am I missing something? Does it?