Im with Tim... if you dont want to get him a 350, but would like to keep him V8-Throttle-Happy, an LB9 or LO3 might work. LB9 is a 305 version of the L98 foff was talking about, with a Tuned Port Injection. Its pretty decent on gas, which perfectly fits a high-schooler. The LO3 is a 305 with a fuel injected Throttle Body, and from experience of owning one, it is the best on gas mileage. I drove from the middle of Morris County to the Poconos on Rt 80 and didnt even use a 1/4 tank of gas
If you wanna stick to getting him a third gen, get him a camaro, so he doesnt have to deal with headlight motor failures like I did
Again like what foff said, a 93-97 F-body with a 350 LT1 motor can go from $2500 (high mileage) to $7000 (low mileage) and has the looks a high schooler wants
Good luck [/2 cents]