ccmichael48

i mic my cylinder bore in my chevy 7 of 8 are 4.031 my number one is showing 4.037 can i run 30 over rings and my ring gap is showing 0.080 crazy gap doing my first rebuild could really use some good advice

old dog

if you have standard bore piston's you are probably at the point of needing to have the block bored and new piston's and the correct size ring's . you probably have a lot of taper in the bore .if you cant bore right now a temp fix would be cast iron ring's ,they seal up better in a worn bore .

ccmichael48

They have been bored already to +30 just wanted to know with what I mic if I still could run +30 rings n be ok

old dog

.30 over is the only size you can run unless you get a set of custom fit rings and get a piston ring filer . these spec's are only a guide line top compression ring example
.004 per inch of bore .016-.018 intermediate compression ring .020-.022 .the custom fit ring's may come with spec's to follow .depending on the intended usage the spec's may have to be opened up more .

J.W. Racing

Needs a rebore; but you can use an oversize ring (.035) and file it down to the gap you desire.