New GT-40 Crate motor

I just put a brand new GT-40 "340" hp crate motor in my car, bought the timing chain cover, crank dampner, and whatever else kit, i finished the motor with ALL new parts Nothing fell in the intake, as the ford tech guy keept insisting. I now know this, because after talking to him, I ran the car and disconnected and replaced one wire at a time and it still makes a bang out the intake(meaning the valve is open), and the car still banged with every cylinder disconnected at different times, so unless more than one thing fell in, which I was persistant in making sure not one thing did, the cam timing is off. The rockers on this motor look stock and all look and feel like they were installed correctly. Is my only option to take off all of the accessories and check the timing chain? A mechanic suggested that he put shims on all of the rockers, would this have any effect, or could this be a bad idea? He also said that it may be too high of an octane(93) but we have had the timing from 10-20 degrees and nothing..............
AHHHHHHHHHHHHHHHHHHHH
Please help, and how do you change the cam timing with the chain if it is off by a link or two...

yea thats what i think, the engine is from ford's engine plant, brand new, and if ford can screw that up, im scared.

I'm pretty sure they will take the engine back, but I may have to ship it, and i need my car! I talked to the tech guy and he made me believe that sending back the motor was no big deal, but since I have had a mechanic look at it, I dont need any more useless expenses. He's going to charge me and Ford Racing better pay shipping. Anyone have an idea on what else i can do?

also can i just bring it to a ford dealer, there's one like 1 1/2 mi. from my house...

thats really bull, it's a ford motor, ford should have to pay for their mistakes, not me... I guess ordering a motor and thinking that because I use all brand new ford parts, my car will run right is my mistake.