Did you replace cam bearings?

I hate to say it but replacing bearing shells without turning the crank, or polishing the journals, could result in a main or rod knock. Did you look at the shells when you re-torqued? Were any scratched, or sign of a rub? Did you mike any of the journals during the rebuild? Were rods re-sized?

When I was young and poor, I'd do that kind of rebuild without a second thought. It's a crap shoot that the rods and the journals are really round. Hard to believe a new set of shells would make things worse, but it can.

 

A flywheel will produce a very distinctive knocking sound if it is loose. If you open the throttle and raise the engine RPM, the flywheel will produce a Sharp knock just as the engine speed reaches its peak and starts slowing back down. The flywheel is very heavy too and you should be able to feel th whole engine move at that instant.
A warped flywheel will vibrate but won't produce a knock.
I would use plastigauge on the Rods and mains to confirm clearances
Also, when you plugged the fuel pump bushing, did you plug off the bottom end of the hole? The oil will leak through the bottom of the bushing and onto the cam. Yu would think the oil pressure would be low though.

 

Did you have a knock when you first rebuilt the engine? When did the knock first start to be noticed? Did you check the rod journals when you replaced the rod bearings? Is the noise the same with a slight load on the engine? does it get louder or quieter with load? I knew a 12 year old kid who rebuilt a 1953 flathead v8, replaced the fuel pump with electric, put a plate over the pump hole but left the pump pushrod in the hole. Tore the whole thing down and still had the knock. 51 years ago! My supervising uncle was an expert mechanic who let me use his tools. He knew what I had done but let me make mistake after mistake till I learned how to troubleshoot anything mechanical.

 

Yes I checked the rod journals. Ran and sounded great for a long time, one day after a 40 mile jaunt it started rapping. Oil level and pressure were good. Noise relates to engine rpm. It has seemed to get louder as time has passed. I have not ran it much in hopes that the can of STP oil treatment I poured in would make it go away.
Wish it was as simple as a fuel pump rod...It's in a box in the garage.
I also know of a young 16 year old (50 years ago) who with equally less than knowledgeable friends worked on a "48 Ford Woodie (wish I still had that beauty) and after rolling it out of the garage drove a friend home only to leave a really large puddle of oil in the friends driveway. No one told us you were suppose to put the dip stick tube back in. His parents were quick to let my parents know that we had a mess to clean up.