Hi I'm new.i just bought my truck last week.its a 2002 silverado 2500 duramax diesel. 6.6.i am a welder and I'm finally putting my truck together.how can I tell if my truck is 3/4 or 1/2 ton? Should I put airbags in? The welder is like 1300 pounds plus torch and tanks, and tool box? Prob a...