Small block motor mount question

Duster360LA said
That's correct, but the notches in my K member "ears" are half-inch wide, so any larger of a bolt wouldn't fit - unless I carve out the mounting notches (which I don't want to do)

If the standard bolts are 1/2" and the hole in the spool mount is 0.6" there is no reason to up size the bolt. That was my point

I would never suggest modifying the car to fit a part.