so i am rebuilding a 010 350 engine and i took the bearings up to the engine shop and had them verify if it was standard or oversized. they were standard. so i picked up the bearings and rings for standard sizes. got two pistons cleaned and installed then i thought to look at the markings on the actual pistons. i would guess according to this it means the block was bored over .030? i measured with a tape measure and the cylinder looked to be 4 inches but that is with a tape measure not a mic. the standard rings seemed to fit fine but i am guessing i need a 30 over set?

 

.030 is .030 oversize. You will need .030 rings. You can place a top ring into the engine bore and check the end gap. If the ring doesn't fit or the end gap is to big then you will know you have the wrong rings for sure.

 

according to the stamp on the piston it is .030 over right? if it is oversized then the gap would be too large. they fit in because i have two pistons in with new rings but of course they would fit if it is oversized i guess. need to pull the two out and see if i can exchange them for some .030 over rings

 

Yes .030 over pistons is correct. Yes it sounds like you need to swap for .030 rings.

 

Have to check everything
Size of crank journals has no relationship to bore size.

People are out to save $$ so will only do what work that is needed Quite possible as in your case for cylinders to be bored oversize but crank to not need grinding and been left std size.

 

Yes need to check everything. I have seen engines with with one cylinder oversize and others stock, and cranks with one journal .010 under and all others standard.