I just got the 4 bolt main 350 block with a lot of accessories really cheap. Its got a very lite rust on it that needs to come off. So I called around and I found that a local place will do this abbrasive blasting cabinet thing where i guess they put it in an oven or something and then sandblast it with a sort of metal powder. I know nothing about this but he said not to do it unless im planning on boring it out afterwards because it leaves a ruff finish on the block. I am boring it out afterwards but my question is, if it leaves a finish on the cylinders that throughs them off, then wont it mess up the other areas? I mean, like wont the lifters not fit right and the bearings and such? Lemme know if uve done this or whatever... I need to get this rust off someway or another... Thanks in advance!

 

I think I would try to hot tank it first. That process is pretty good at getting most stuff off including rust that isn't severe. You are right it would rough up the cylinders and lifter bores. You would have to hone them out. Not a real big deal depending on how much they were roughed up. I think if there was any rust left after the hot tank then I would just tape off the bores and other holes and spot sand blast it. I would feel more comfortable doing that.

 

take it to a machine shop. if you're going to bore it cleaning will be part of the process.