Paul beat me to it on the timing gear/chain problems that Pontiac had back then. The original camshaft timing gear was an aluminum/nylon combo that usually failed in warranty, at that time 5 years/50,000 miles. I still remember the part numbers for all the associated parts.
The other issue that comes up also, if whoever changes the gears and chains does not drop the oil pan and clean up the sump and the pickup screen (partially shrouded) the screen can clog up with nylon debris and restrict oil flow.
I saw a lot (and worked with) a lot of hack mechanics back then that flagged the job, stashed the oil pan gaskets under their bench and hoped for the best. And when it came back for a oil light on at idle complaint, then they would drop the pan, call it a oil pump failure and slap in a set of rod bearings.
So, it might pay to pull the timing cover and see if the cam gear is a aluminum/nylon or a all steel one. At least for peace of mind. It's not a big job seeing that it does not have A/C.
The only other thing, in '69 Pontiac had a problem with water pump failures.
They redesigned it, interchangeable except you have to use the correct water pump pulley with it. It was late in the '69 model run that this change was made. Safest way to get a replacement is to take your old one and match it up.
Also, if you change the water pump, there is a metal baffle behind the water pump. Before you turn in the old pump core, make sure that you remove it as the replacement pump will not have one wither on it or with it loose. And the pump should contain two gaskets, one between the pump and baffle, the other between the baffle and the timing cover. If this part is not installed, the car will definitely overheat. If yours has any pinholes in it, new ones are still available from GM.
Hope I didn't bore you, but I've owned "real" Pontiacs since 1970 and presently have a 428 car in the garage. Unfortunately not a pro car though.