Not bad at all but you are WAY WAY MORE than 20 percent.
You have about 100 lbs to lose at least.
I disagree.
Lets say he's at 25%.
Getting to 10% would be a nice start, after getting into things. He would be very conditioned then, pretty ripped.
15% of 310 lbs... Approx 46 lbs. Lets add a few pounds, muscle waste or whatever. 50 lbs.
Which means he should be able to weigh in at around 260 lbs after a diet.
Realistically though, I think he should diet for maybe 3 months (12 weeks), which would put him somewhere at around the 275-280 lbs mark IMO. Then eat a lot through February, put on some weight, and then diet down for the summer 2007.
YIP
Zack