Ah that's why, I was going to ask...
Yes. Grind the heads.
The taller roller lifter locates the push rod in a more angled resting place...then motion angularity increases...so you grind the bottom outboard and the top inboard toward intake. That is what you have to do to run a roller in a 59 degree lifter angle block/LA small block mopar...also your geometry kit shifted it all toward the intake and exaggerated the issue, plenty fixable though and very much worth it to run the kit.
I run 5/16 smith bro push rods, I would stay with that size and grind the heads, not go smaller. Easy and fairly quick fix with aluminum .
