I've been looking for a 4 bolt main 350 sbc for a while now, and I finally seem to have found a steal. I went and got it just now, kinda late, and it has some light surface rust on it. My friend, who's basically a genius when it comes to this stuff, doesn't seem to concerned with it. He's saying NAPA can get it all hot tanked and buffed out fer like $40. Is that right? I mean, can they get the rust off and everything? And since its rusted is there a bigger risk that things won't seal right later? It's an awesome deal, I'm getting like brand new federal mogul .30 over pistons in the box with it along with everything to make it a long block for $250. Just lemme know if this rust is an acceptable thing. THanks!!

 

I've seen some motors that had some light rust in the bores and on the head gasket surface, and after the rust was removed by sanding they we're ok. The bigger concern should be whether or not your block is bored and honed to the correct size for the pistons. It doesn't sound like the kind of deal you'd want to just put together and fire up. At least hone the cyls and mike em to be sure they're the right size for your slugs.

 

Boring out the block .030" will more than take care of the rust. As stated above make sure it hasn't been overbored already & bore & hone to fit the new pistons, this is critical.

 

yeah depends where the rust is at.. is it in the cylinder bores or is the outside of the block just rusty? if there is rust in the bores and its light you can probably get away with a hone but if there is any depth to it your gonna havta bore it..... keep in mind a 4 bolt main block really isnt anything special, they're stronger then factory 2 bolt blocks for the most part but if what your going for is strength then a 2 bolt block with splayed mains would be the way to go, or better yet an after market block with splayed mains..