i would prefer to put the fiber gear back on instead of the aluminum one (noise issue). probably not the smartest move but i figure i will be long dead by the time the new gear hits the 50 year mark and potentially fails. then it will be up to my daughter to figure out how to fix it. if the fiber gears are only expected to last 50 years, i got by pretty good given that it was almost 60 years before it failed.
i was already planning on utilizing an oven to warm the part prior to installation since it has the best chance of being heated evenly and under controlled circumstances.
if by stale you mean old gas, that would not be possible. until the time of the engine failure, this truck was my daily driver so it always had fresh gas in it. the last time this truck potentially had any stale gas in it was when i bought it off of my grandparents farm sale in 95.
more as it developes...
