Latest update,
I ditched the previously ran npi ported heads due to detonation issues. Although not recognized while running, the head surface showed the signs and to clean the deck up would take roughly .030" cut and they are already .120" decked. These particular heads found on any npi 4.6l have substantially less water cavities compared to any pi head and the 5.4l npi head.
The detonation was visible only around the quench area of the chamber and along the gasket bore meaning nothing to do with combustion detonation, but hot spots tucked between block and head surfaces on the gasket bore. A diameter that is typically .100" bigger in diameter than the cylinder bore. Micro automatic combustions.
Wanting to keep the under dog scenario, i wanted to keep using npi heads, but i had No luck sourcing a set of 5.4l npi heads at a reasonable cost. Im not spending the going salvage yard rate of $300 for a set of whats coincided by most to be junk worthy.
Moving forward i have decided to go with a set of worked out 5.4l pi heads. Not 100% sure of the differences between normal 4.6l pi heads and 5.4l heads, but these heads clearly embossed in the aluminum "5.4l".
Mild porting, some seat work and a few other trickerys will make for an interesting learn. Bumping compression down a few points not on purpose, just running the head as is drops the compression. Roughly 11.5:1. Due to availability I can always grab another set of pi heads, work them over and deck them real good to get even crazier compression ratio should the success of this build plays out well. Given the better cooling aspects with these heads and strictly running E85, any increased ratio conjured up shouldnt be a problem.
My main concern is valve seats dropping out and blowing out sparkplugs...Typical pi head flaws!