yes, burnt gaulded pistons, running hot, slow cranking etc. I would not go over 2 degrees max - if you want to explore unknown territory. I am sure someone will say they have been running one for 20yrs this way - but I would not.
Allis-Chalmers started using the American Bosch pump in '82 and smoke levels become quite acceptable. If an '82 smoked abnormally I would replace the injector tips even if they checked out ok. It is hard to eyeball the pointer to fuel pump gear hub on the American Bosch and be within a degree or two from what they call for. I would be carefull about changing timing much from specs. I have went a couple degrees advanced to reduce smoke on Roosa Master systems but not before I know I have good injector tips. Advancing will normally hurt the starting situation when cold. Vibration damper pulley has the timing marks on rubber mounted pulley. There have been times where pulley slips on rubber which throws off the timing marks so this should be checked before you tweak timing one way or the other.
Also I have had tractors and skid steers come into shop with complaint of smoke and found injectors in 180 degrees from intended position. If in question, pull the valve cover, get a service man and find TDC or pull n1 inj and insert a soft solder stem from a roll into the hole and use this to obtain TDC - half way between the start of travel as the crank is rotated cw and ccw with piston at top. Who ever ran an engine this advanced had a bad TDC to start with or a pump that was bad.