Ah, so that AEM sounds like a different cam gear than I saw on a video. They installed everything and it was still in the engine stand and they'd been spinning it for other things when someone noticed a clicking or something. They took the belt back off and discovered the cam gear bolts on the back were hitting the block or a bolt. I think they machined the bolt heads on the back of the gear for clearance, and I'm pretty sure it was the intake cam like yours.. Anyhow, that's a definite suspect and I guess the thrust movement of the new camshaft would also be curious to measure. I'm sure your shop knows this, but be very, very careful about torquing down the cam journals. Into aluminum, bolt torque doesn't "fetch up" like it would into steel. The proper torque feels like it's smearing into correct torque. I used a beam style where you can get to the right torque and hold the tool in place for a second. If the beam "unwinds" (the fastener turns), then you're not at the right torque. A click you can't "see" this..