Hot knock

I put together a 74ish 360 piston rings conn bearing cam bearing heads freshend and after about an hour at 190 degree it started to have a faint knock that is also intermittent.This week the motor will be pulled and torn down. I myself am aimming for conn rod bearing, Know I had a guy tell me he had an old aspen or vega and it would get a hot knock after an hour or so he pulled the motor apart and could only find a cam bearing blocking half a journal.....doesn't make much sense but when I got my block back from the machine shop my middle cam bearing was spun blocking half of the journal. Any idea's