Is it ok to bore a 502 gm block to 4.6 bore. Casting number is 10237300 Gen VI block 4.466 bore
It is already .60 over and needs to go further
Thanks

Sorry that is not very clear, the bore right now is 4.56, it is scuffed and needs to go further, is 4.6 ok on this block?

Standard bore on a 502 is 4.470. I just bored and stroked mine to a 540. That was done by boring it .030 and stroking it .25 inch

sorry that was not very clear. Right now bore is 4.56 and is scuffed and needs to go further. My only option is go to 4.6. Is that ok on this block?

Most of the time they can be. It would be a good idea to sonic check the block to make sure. If the bore will clean up at less of an overbore, you could get custom pistons. That will leave one more overbore in your block.

tx,
Unless I am thinking of a different block, GM only recommended 4.500 as a max bore so you are already pushing it I would say a sonic test wuld imperative to go much further.

Bill Koustenis
Advanced Automotive Machine
Waldorf Md

I actually thought about custom pistons and called JP today. They are more affordable then I thought since they have a off the shelf piston to spec and can just make it .001 to .002 larger. Actually it is only $5 a piston more then list. So this is the route I will likely take. I have a nice set of srp 4.53 pistons with 10 hours that I was plannind on reusing so this is kind of a big hit to my engine budget.

Sounds like you are on the right track. Most marine guys do not like to bore more than 60 over. I bored mine 30 over to allow for future rebuild. Bore as little as posible. I guess the scratch is to big for honeing?

Honed it .005 over to clean bores. still is going to require costom piston. Going with diamond pistons, that is what my builder likes. What do you guys think of diamond? JE and Diamond were comparable in price, but he suggested Diamond

Diamond is great. Eric will take car of you. They get the customs done a lot faster than JE and you can actually talk to someone pretty easily. I am getting ready to order a set from them for a Drag engine in the next day or so.

Bill Koustenis
Advanced Automotive Machine
Waldorf Md

Thanks for the advice Bill, you are always quick to help out, even a new guy like me