85 is to much way above book spec which is 65, on a Chevy you can pull the threads right out of the block. Yes depending on who's gaskets you used they may have needed to be re-torqued after it was brought to temp! What you may experiencing is too much water pressure, head gaskets will only tolerate about 35lbs. It is very common for the gaskets to weep on raw cooled engines, I would guess that 25-30% of the raw cooled boats I have serviced weeped somewhat, the newer better gaskets hold better but still not up to high pressures. Phil
No matter what your beliefs are "GOD BLESS AMERICA"
Fully retired marine tech near 60 years in the biz.