[Jeff Chambers]

Sixty over on a stock block isn't that good of a thing. The bores start to get mighty thin at anything more than .040 over. You'll probably be alright if you're not planning on flogging the crap out of it with blower or nitrous. Sounds like you got a non-roller block too if it wasn't drilled and tapped for the lifter retainer. Are you sure its got a roller cam in it? I think I'd be on the phone with the builder to find out just exactly what you've got. Ask plenty of questions:

Roller/non-roller block?
Block & crank magnafluxed & checked?
Roller cam? Specs on it?
Crank & balance (28/50)?
Is the assembly balanced?
What types of bearings & clearances?
Why 0.060" over?
Clearance on pistons & final hone?
What type/size of rings?
Thrust for manual/auto?
Decked & squared?

Let them know that you're trying to be an informed consumer and also let them know that if you're suspicious about it that you'll return the motor and expect a full refund.