Can they be just 'swapped out' like rod bolts?

 

After you clean the bolt holes out, then yes...

 

Well it's a new shortblock it just doesn't have the ARP main studs. I didn't know if it would mess with the bearings at all.

 

damn dude I am sorry I thought you said head studs for some reason...my bad.

 

If it has the stock GM bolts in it leave em there, they aren't really a problem area in those motors. You might get away with it but when you install studs into a block you are putting different forces on the block than what you would with bolts. It could slightly warp the bore. To properly do it you should have the block line bored to ensure it's 100% dead on.