this is one of the problems with torqueflight transmissions.the torque convertor drains in park,and doesnt refill until you put it in another gear,so for a few seconds,there is no fluid while the torque convertor fills.obviously,this shortens lifespan,and several years of doing this can take its toll.does it slip in any other gear,or just the hesitation upon startup?
id change the fluid/filter,maybe even a couple times,just to make sure that all the old fluid is out,and form now on,put it in neutral for a few seconds before you take off.ths will save alot of wear,and prolong the life considerably.
a rebuild is in the future,but it may be another few months,or maybe 5 years from now,if it doesnt exhibit any other symptoms. the one thing ive really learned about auto trannies,is that its real hard to predict what theyre gonna do!
85 grand wagoneer
258/904/twin stick dana 300/dana 44/amc 20
38x15.5 gumbo mudders
snorkel/dual batteries/onboard air/"custom" convertable
3 inch body lift/mostly stock suspension/"modified" fender openings
custom front/rear bumpers and brushgaurd