Just finished my 440 big block build and 727 trans.
Was going to bolt up the torque convertor to the flex plate and then mate the 727 to the 440 and figured I'd use good ARP bolts.
Are these the correct bolt kits I would need?:
Depends on what converter you have. The factory used 5/16 bolts. Some lower cost aftermarket converters use the 5/16. The better converters will use a 7/16 like you have linked to above.