Cadillac Forum - Enthusiast forums for Cadillac Owners - 97 SLS KNOCKING LOUD after head gasket replacement.

Car was overheating at 75K. I changed head gaskets by dropping frame from car. Surprisingly had no need for new threads. Replaced numerous gaskets that I came across. Cleaned and expected all pistons and valves. Noticed 4 of the 32 valves were open. Thought it would close during engine operation because engine never knocked. I did fail to lubricate the piston walls after cleaning. Thought I timed it VERY precisely with angle ruler.(((((((((((cams are 90* from cylinder, cam chains had slack were needed, two crank sprockets faced each other, chains slack are fine.))))))) So I fired her up and heard a very light knocking noise. Out of frustration I decided to do something easier. I disassembled the starter, cleaned it, lubed it, and screwed it on tight. Again I never experienced issues with knocking so I didn't bother to wiggle flywheel to see if it was loose/ broken. Starters teeth were stronger than mine. After biting the bullet I dropped it again to be 100 and 10 percent sure I timed it correctly. I started it up and the knock was 10 times louder! Attempted to time it x number of times and it is still loud as an elephant knocking at your door.

Questions:
Could the knock be to the pistons rings worn/bent rod/worn rod bearings?
Could it be a flywheel broken?
Could it be bad valve springs/lifters?
Could it be not timing it right after countless attempts?
I noticed that the wire harness connecting to the distributor is missing metal connections. Went to the junk yard and found the harness there had identical missing connections as well. Was convinced its exceptional but is it?
Finally, on 1 of the 4 distributors the number 7 is below the 6. Which spark plug wire connects to the terminal for the 7, left or right?

THANK YOU FOR READING MY POST.

Suggestions are more than appreciated.