Yukongt2818

Ok so i spun a rod bearing in my 97 yukon gt after looking at all my options I ended up buying a used tbi with a recent a c Delco engine rebuild (proven) only it blew a head gasket tore both engines down leaving crank rods pistons and nothing else and transfered all my vortec parts to the tbi block except for the roller cam I installed a cam from a trusted friend who said it would work with my computer as I'm aware they're sensitive to cam upgrades it was a ft cam shark tooth heads same intake upper and lower truck fired and idle with an extremely hard cam lope soon as you touch the throttle it looses all vacuum and fuel just won't run went back to the stock roller set up everything back hooked up dist. Stabbed right tdc on compression valves adjusted accordingly tdc 6 remaining valves adjusted all buttoned up just cranks won't start 60 psi fuel pressure no spark at plug went back to coil nothing out 12v in so I thought coil changed coil and module beside it same thing all ecm fuses etc good crank sensor and wiring good all ground good I'm loosing my mind as this is my only vehicle any help greatly appreciated