Villian profile: loose pre-flop caller, will go all in with strong hands or draws.
Stack size

Game .25/.50
Hero: 170
Villian: 86

Preflop
limp, hero raises to $2.50, villian calls, limper calls

Flop
J 7 9 rainbow
check, check, hero bets $5.
Villain calls, early limper folds. heads up now

Turn is a 2
check, hero bets $8, villian calls

River is 8
Villain goes all in for $71
Hero folds

What would you do? I haven't seen him go all in with just one pair. He was tilted from previous loss and desperate to get it all back which inclined me to think about even a call. My logic was it's very easy for him to have a 10 or just two pair like J8

Just call 1 pair on a 4 card straight board. By the way you describe his play he might do this with worse than a T but alot of worse hands just beat you. Good fold

I think it's a correct fold, the villain probably had AT.
i don't play in this limits, so i can't talk about your bet size

Looks like a solid fold vs this line id play it the same way.