Will it fit? Yes? No? Maybeso? any suggestions i have some parnelli johns 36-14.5-16 and im not sure if they will fit on 16x8 rims. Any info is good

Yeah they will fit, but will wear pretty good in the middle.

well im use it for the trail only so i am thinking of keeping the air pressure down

For the trail will be fine. Narrow wheel/fat tire will help protect the rim too along with airing down without risk of popping the bead.

run it you will be fine