Need help with several questions

[LawMan02]

Hello everyone. I'm new to this site, but must say it's very informative with all the knowledgeable people that log on and a great site for someone like me that has no great mechanical experience to find the right answers.

I've owned nothing but pick-ups throughout my life, but never a truck that needed much work...until now. I just purchased a 1972 GMC K2500, lwb, with a 350-V8 and 4 speed transmission. It has 32,500 miles and was a truck used in a fire department in Indiana. The body seems to be in good shape with no rust and the motor runs great and the drivetrain seems good also. I haven't driven it since receiving it on Sunday. It also has a Ramsey PTO winch. I'm very excited about repairing the few small things...valve cover gaskets, interior work and some minor exterior work. I also would like to put new tires and rims on it. This leads me to my questions.

1) I would like to put on a set of 35 x 15.50-16.5 Swamper TSL/SX on 9.5 X 16.5 rims. What would y'all (from Louisiana) think the minimum lift the truck needs to run this tires?
2) According to the tag in the glovebox the truck has a "power lok" rear end. Is this a true postive traction? Will I have trouble with the rear end running larger tires?
3) There are fire department stickers on the truck and I started removing them with a hair dryer and that seems to work fine. Is there an easy way to remove the remaining sticky stuff without damaging the paint?
4) Last question...With the truck being a fire truck with lights, antennas, radios and accessories, there are a number of drilled holes in different parts on the truck, exterior and interior. Any suggestions how to fill the holes other that bondo for a temperory fix. I would like to cover the holes and maybe later come back and repaint the truck. Thanks for any help. Randy