Depending on which book/manual, you read the CR for a slant was 8.2-8.4 to 1. I never did a 198 engine, but any 170 or 225 I took apart and measured while disassembling, was never more than 8-1 CR. All except for one engine was in the range of 7.8-1 CR. That was with the factory shim head gasket. If doing nothing but a repair, and replacing the head gasket with a aftermarket gasket, the CR got even less.