When tightening down square taper cranks, typically how far down the spindle (mm?) will the crank arm sit from the ‘zero’ position; ‘zero’ position meaning put crank on, hand tighten down the crank bolt until the crank doesn’t move.
I’m no pro mechanic, but since its a Phil, check the DS and NDS at the same time. If DS is also touching before you start cranking, you’re miles off. But if there’s room there, play with the offset (bring the NDS out) and see what you can do. Hitting the chainstay before tightening with an allen key sounds like you’ll need something longer.
Again, this is word of an amateur, but I think grabbing a couple of cheap shimano BBs will let you find the right length before buying another Phil… tapers vary a little, but I doubt the “right” length shimano will be the “wrong” length Phil.
75’s are ISO and he has a ISO BB
The length will be different from a Shimano (JIS) BB.
FWIW i’ve run 75’s on a Shimano (JIS taper) 107mm BB and on a phil (ISO taper) 109mm BB
If the OP already has a 109mm ISO phil and is getting interference the frame might be the problem in which case a longer spindle might solve the interference problem but at the expense of the chain line
Gorillaring = tightening. Generally I apply the “gorilla” in a sentence when referring to something thats unecessarily tight. This time just for lols. I’m running 75s with a Campagyolo pista BB on a gazelle road frame with 130 between the drop outs and the crank arms are close to chainstays’ - like a few mm but works well. The 75s didnt move back much when I tightened the bolts if I remember correctly.