After the trip to Beaverlac, I still detected a slight pinging, pr pre-detonation coming from the engine when under load, hitting a hill etc.. It really sounds bad, lots of clatter coming from within. After a lot of helpful correspondence from Tony my mechanic friend, I decided to re-time the motor properly, dialling in more retardation to get rid of the pinging. As my pulley doesn't have multiple timing marks except for TDC, this was pretty difficult to accomplish. I managed to dig out my old marked up Empi Pulley, and measured where both 7.5' and 28 degree's BTDC, and marked the pulley using a silver permanent market. Then re-timed the distributor while revving the motor up until the advance stopped and the marks stabilized. This was pretty much 28 degrees on the button. Idle was a little lumpy but I balanced that out with the carb sync tool and opened up the jets slightly. Engine sounds awesome now, I can pull off in 1st and go straight 4th with no hiccup or stumble.
Dirty engine after the sand roads, but the gap shown how far BTDC I set the timing at. 43.5mm's.