I do know the history of the heads, they have been decked & compensated for with a thicker metal HG.
I looked at the replacement exhaust cam and it looks like the pin is in a slightly different position in relation to the bolts on the cam in the engine. It runs great now since i replaced the main fuse with a break in it, but i'm going to swap the exhaust cam out to get it back in the centreline of the CAS @ run it at 15