So a compression test shows 70 psi? It's always good to do a test of the crank seals. but......as I understand it, crank seal condition has no bearing on compression. If you are confident that your compression is only 70 psi, then it would seem best to concentrate on piston, rings, cylinder and head. Also, I thought I had a low compression Super 8 2T (35 psi). Turns out my new Harbor Freight tester was wrong. I borrowed 2 other testers and got readings in excess of 135 psi.