Dana 50 perches

Should say Dana 60! Just about ready to get my perches welded. Curious as to how thick the dana 60 tube walls are? Ive googled and seen .250 and .313 but nothing definitive! I was going to set my pinion and tack them and have it welded but If its 1/4" or more my little welder isnt up to that task.

Which brings me to this. If i cant tack them in the car whats the best way to mark them so that when i do pull it im able to get the pinion angle back to where it needs to be?