me and my cousin are thinking about doing a rebuild on an old 5.0 engin out of a 1989 mustang that has been sitting in his garage for a few months and we arent sure wether or not to bore out the block. if it is sugested to bore it out what should we bore it to we were thinking obout .030. would that work?

 

take it to a machine shop, they will know

 

Well i called and they wanted to know what bore i wanted so i believe that a .030 would be perfered because that is a very highly known bore. but i just want my car to be seriousl fast

 

Seriously fast has to do with a lot more than just bore
a .030 bore is a great way to clean up cylinder walls/put in some nicer pistons, with that you could also stroke it out to a 347 or some variation if you wanted. If you want more displacement out of the block, well, don't bother. .030 is probably ideal for your needs. Easy to find 4.030" pistons, anyway

 

lol, seriously fast isnt somethin u get rebuilding an old motor sittin in someone's garage. but yeah, you'll prolly have to bore it .010 over just to get out some imperfections. Unless your stroking it, the bored has a very small effect on displacement. The more metal you have b/t your cylinder walls the stronger/more reliable the block will be. What are you driving now? If you're driving a newer 5.0, a simple rebuilt motor won't do much for you as far as going fast