Sc scoripon

Hi, I just bought a project boat'39 crisscraft . This boat came with 250 b&m sc x 2 . One motor blew head gaskets front two cylinders l and r. Motor rebuilt, on my garage floor now. Other motor still in boat. I did compression test, got 160 all around. This seems high to me . My pulleys are 6 in bottom, 3.5 top. Any one have any sugestions,or tech advice to help out a fellow boated who's down on his blower knolage?

Sc scoripon

Also, the compression test was done with the sc belt on, thinking to try it with belt off this weekend. All the spark plugs were removed during this compression test.