i have a 351 R block...9.2 deck height, 4-bolt on 2,3,4 mains, and bored .030 over...frpp says these blocks can only be bored .030...how many people have seen these bored larger... .040????maybe...it is a non-siamese bore block also
The W block can go .040 with ease.. we have run .060 over with 9.5:1 comp and NO problems.. Usually the Mfg is real conservative !! but thru experiance.. .040 is good and .060 if you need too!! cool??
.040 will be fine on that block I have the same thing for my car, half filled with Harblok also. You can sleeve it down if you need to. I know builders who have taken them out to 4.080 with no issues.