I have the mig135 and need to fix a crack in a transmission bell housing. I was going to order the spool gun BUT would I be better off using the mig175 for the repair than the 135. The aluminum is 3/16 and the crack is about 3 inchs long by 1/16 wide and doesn’t go all the way through. The 175 would be a replacement for the 135 and cost was a factor. TIG is out of the question.