My money is on the t-stat installed upside down. No other reason for an engine to over heat in 2-3 mins. at idle. If that don't work, call Summit back and order a 528 hemi, that'll fix your overheating problem...hehehe
With his dads knowledge of cars I find it hard to believe he would let the kid overlook the t-stat. But hey...something's wrong. A 528 would fix a couple of my problems. These screaming small blocks are getting hard to deal with.