Not my mopar, but need advise on 5.7 vortec chevy

Had my work van in to have the injectors replaced and got a call that there is a crack in the cylinder wall. It looks like I need a whole motor. It's a 98 votec 350 chevy , it's a Grummans panel van 3/4 ton so I would say I need a 4 bolt main truck motor.
I looked at Summits and ebay. any suggestion. Thanks