T56 magnum install 69 Cuda

We are looking into various shops to build these 2 parts. The torsion bar frame support and the transmission mount. It looks like these will need to sell around $700.00. I think we can get them down to about $600.00 if we get 10 or more, and can make a run of them.
Let me know what you guys think. Mine are made out of 1/4" carbon steel. I think 3/16 would be quite strong, but it really doesn't affect the price much. Please give me feedback so I can either bail out, or move forward. Thanks so much guys!!!! Todd

Does it have to be carbon steel? That seems above what is needed. Couldn’t it just be steel? Your design looks solid enough that you could fab it out of aluminum and still maintain structual integrity.