On a GDLT, RPMS OOW running 4500-4600. RPMS under a heavy hunting load 2600 at best. Motor is still running really low, but this was not in mud at all, even lower rpms in mud. Still think my linkages are off on this engine. I see no reason an engine can spin those rpms out of water and be cut in half without there being some mechanical issue. Have not done a comp or LDT yet..

Any thoughts before i go tearing into it?

IM beginning to think I have an intermittent spark problem going on, fairly common on these engines. after some searching Im certain i have a DSAM ignition on my Kohler. Kohler came out with an MDI kit for the coils.

Anyone here have any knowledge of this swap? or improvements made between the two? Going to check spark on my engine next to see if one side is intermittent.

I would do the testing u mentioned first. Also pay close attention to the valvelift. The kohler has real valvesprings “hi pressure” to run hydraulic lifters. They will eat cams on the wrong oil