For most of the welding I have an older Miller 175, probably 17/18 years old. If I recall correctly its rated to 1/2-5/8 and it has welded alot of truck (semi dump trucks, roll'offs etc.) Its a great welder, for small stuff I'll put .023 wire in it, and for the chassis stuff some .035 and go to town. It doesnt have all the bells and whistles, but comfort I think is a big part.
The rear springs are 110lb. Car roughly 3000lbs I'm guessing. I talked with Bickel about them alot and he recommended a lighter spring even though I could have went heavier. Lighter springs in a heavier car can store more energy while maintaining ride height and respond quicker. The only down side is they will wear out faster but springs arent too expensive. A heavier spring will last longer but in all honesty if springs cause me to loose a couple hundreths, who cares.
Sorry so long.
Andre