Goku lost to cell. Pikkon is equal to goku. Pikkon beat cell. Pretty sure hell has some sort of evil power failsafe or something. But I believe we're getting of topic. Yamcha is a well built guy. I'd say he's about 180-190 pounds. He survived the gravity chamber, so we know he can withstan more than 54,000 pounds of pressure without any injury. He could probably go a few rounds with either spidey or ironman. But not both.
Filler Yamcha is far better than manga Yamcha in my opinion, especially end of DBZ Yamcha cause he was fairing well training in other world, plus the withstanding 300x gravity feat as brief (HAH) as it was back in the cell saga wasn't necessarily that bad >.> ..just saying Filler Yamcha isn't as much of a pushover as many probably think x3.