This guys range is sooo wide. A 40/4 is gonna be limping a lot of hands and a lot of them have us crushed.
This guy will be limping hands 33,99,K9,J9s,A3,A9.AJ,QT and hell he might even be limp calling AK cause Ive seen it done enough times at 5nl on FT and the guys that do it are always the 40/4 types. These hands crush us.
So it just comes down to how many hands you think he calls a flop c bet, donks .30 on the turn and spews the river that you beat but whatever they are it probably wont be enough to make it a b/e call so I'd fold. Unless of course you've seen him go crazy on the river already. Did you take a look at his river AFq?