I've had running small blocks that had such slop in the timing chain,that I was able to remove the chain without unbolting the cam gear!...and a few were not making any noises either,one had rubbed a hole thru the timing cover and cause an oil leak though!....most of the OEM cam gears with the nylon crap on the teeth were "bald" ,all the nylon ended up in the oil pump screen,and the aluminum teeth under them were so worn I felt it was a miracle they still ran,and hadn't jumped time!..
A quick way to get a crank gear off,if you dont ned to re-use it--I use a sharp chisel ,put it right over the keyway slot in the crank gear and one or two good whacks will split it there,they crack pretty easy being grainy cast steel..learned that method from an old timer at a machine shop who felt using a puller of a gear your going to toss anyway was a waste of time...I've done many that way without a hitch since...