Taking 1974 360 block .60 over

You guys act like .060" is the apocalypse. :axe:

Yes, it would be better to go .040" if you can. And if you're really planning on making a ton of power, then it would be best to have the block sonic checked so that you know what you're dealing with.

But I wouldn't worry too much about .060" over on a mild/moderate street engine. I'd venture that there are a heck of lot more 360's from the 70's that will take a .060" over bore just fine than there are that won't. And if you're planning less than 450 hp, I wouldn't stress out about it. Now if you're planning a big money build, then it might be better to just go find a standard block, core 360's aren't all that expensive. Unless you're talking about a matching numbers gig.

If you're really concerned about it, the only way to ACTUALLY know is to have your block sonic checked.