Opinions needed on Tow truck - Diesel or Gas?

[Pantera]

My truck is a dually 454 with TH-400 auto and a Chaprall sleeper on the back window. It was used by a SCCA vette racer and we took it to the west coast one time and he had a 3 wheel 42 chapparall and it weighed 25,600 according to Arizona when we went through there. That was with only one 3,300 lb corvette and some spare motors and such. Have you ever weighed your rig? That seems too light to me.