I'm assuming you are talking about the bellhousing bolts.
IIRC, it uses 4 3/8-16 bolts on the top and 2 7/16-14 bolts on the bottom.
If your 7/16 bolts don't fit, something is wrong. Either the trans thread holes are screwed up or have been drilled and tapped oversize.
Are you sure your bolts are 7/16?