This all makes perfect sense now. Sorry for being so dense!
Mitch I believe contrary to my earlier supposition, your table
here is correct. The F and Y body / aluminum head tunes have the EOIT target at 180 or BDC of the power stroke, on a closed intake valve. As long as I'm not once again horribly mistaken the value you came up with through testing (0x63 if memory serves) was actually giving the fuel slightly more time to evaporate, not keeping it from being injested into your exhaust system. To move your low pulsewidth injection window so there can be no fuel in the port while the exhaust valve is open, assuming it closes at 388 degrees as in your chart you'd need some value less than 0x3b. Not to mention subtracting some margin for nominal idle pulsewidth, which would need to be converted to degrees at your target idle speed.