I was wondering if anyone knows what size bolts hold the flywheel to the crank and pressure plate to flywheel.

And does ARP make them?

 

Yes, ARP makes flywheel bolts. Part number is 200-2802. Thread size is 7/16-20, and they are 1" long. The pressure plate bolts are a special bolt, and you have to get them from the dealer. GM part # is 10079898.

EDIT: You didn't specify year or model, so those part numbers are for the LT1.