There are LOTS of tricks to bending tubing for your truck. A few things to think about is how strong, and how straight?? So, you might want to stick to .095 or more for 1" dia. and, .120 for 1.25" and 1.5" tube. If you want to bend 2" tubing, make a template of your outside shape, if possible, and take it to a shop who will bend it for you. You CAN heat and bend tube... it has been done for about 100 years. And any chopper shop will make a fool of you if you say they can't do it. Your major bends can be bought online, or from a shop near you, I am sure. Use I.D. sleeves for your connections if you do it this way, as the joint becomes more durable than just butt welding, especially with mig welding. Don't be afraid to heat steel, it is how it got formed in the first place. The problem is with spot heat and cooling. Try to resist wetting down welds and the local areas; it can make them brittle. Especially with Chromoly... preheat to about 300f and then let the weld cool off on its' own. It takes more time, but the tube is very strong, and has a great spring quality to it. For bending tube, especially thin wall tube, I have had good success using sand... PM me, and I'll explain the process to you. Good luck!!