Lets build a CHEAP(!!!!!!!) bracket motor!

Unless someone other than TTI makes stepped 1 3/4" headers, you are looking at nearly $700 for bare steel unless you can find them used. Used is fine for a theoretical build but I think you are looking at a long wait for a cheap set from a swap meet. Regular 1 5/8" headers can obviously be had cheap new or cheaper used. 1 5/8" should work fine for that level of build. The stockish heads probably aren't going to overpower the headers.