Can someone tell me just how much the 4.3 L engine can tow comfortably? A boat in the neigborhood of 20ft, would that be over doing it?

A 20 ft boat would be no problem. Make sure you have a trailer hitch that's rated accordingly.

Cheers,
Rob

I've got the sonoma GT and I pulled a '72 Mach-1 (I think 3400 or 3700 lbs plus the dolly) on a car dolly from Minnesota to AZ in overdrive at about 70 or better the whole way. The truck never complained once :).