Building tranny crossmember. Quick question.

Got a quick question. I have a thick ass piece of C channel that I was going to use for my transmission crossmember. The problem is it is WAY overkill. The bottom is 3/8" thick and the sides go from 3/8" to 1/4" thick. It is also super heavy. So I decited to look around my shop a little and I came across this piece of 1.5x1.5 with 3/32 wall square tubing. I put it on my frame and stand on it and it flexes just a little. Do you think it would be ok for a tranny crossmember?