Generally is a 1970 383 block safe to bore 60 over? I know it should be sonic checked. I know each block is different core shift etc. Just wondering in general. This will be for a mild street car.

hi

maby /what size is it now ?

have you considered .040 os ?

Why take a chance
Are you filling lucky

Does it need to go .060 over? I always use the minimum over bore. I think the rigidity of the thicker cylinder wall outweighs the small cubic inch gain.

Thanks for replies. Block is 30 over now. But has a pretty good ridge I would love it to only need to go .040. I'm taking to machine shop next week.

the ridge isn't the critical part. bore taper is. once its checked the ridge could be removed with a minial over bore.

I didn't know that. Makes sense though.

Usually if you can feel the ridge, especially a big one, it will need more than .030 I hope not, let us know what they find

Block needed to go.060. Would not clean up at.040. Had it sonic checked and they are putting in one sleeve. This is for my kids car. Bought this motor when he was 13. Put in car and had oil pressure problems. Took it a part not a good as I would have hoped for. Live and learn. He turns 18 next week so hopefully this will be the last of problems.