What head gasket thickness did you use in your 5.9? If the block surface was just skim cut to clean it up but not actually checked, there's a good chance the pistons are 0.005" - 0.010" in the hole. Also, what pistons are they? Icon 745? Lastly, what is the cam's advertised intake duration?
What was the compression ratio of the 440 measured? Sounds like that one is right on the cusp of detonation. I'm curious where the DCR is on that one.
The pistons are Icon 984, for the shorter deck height in the Magnum block. I used Cometic MLS .039 head gasket. I didn't verify the piston deck height, but using the advertised zero-deck, the SCR calculates to 10.4.
