I am geting ready to put my motor mounts and trans crossmember mounts in my '57. I bought the motor mounts and crossmember from Danchuck. They also sell the frame perches for the trans crossmember but they are nothing more than a couple of pieces of angle iron. It is going to take at least a 3" leg sticking in from the inside of the frame to provide a perch for the cross member. I was planing to use 3" x 3" x 1/4". In your opinion is 1/4" thick going to work out well for these perches?