By him saying when he primed it air bubbles would come out I would suspect a cracked feed hose . High pressure pump works like a vacuum to pull fuel from tank . The lb7 did have some injector problem but most of the time you would be getting fuel in oil .
Here is a link to ckp replace
https://gsi.ext.gm.com/gsi/showDoc.do?la...llSyskey=937300. Make sure to ck wire from connector back 6in or so
