[decooney]

Unique sticks with the same frame and suspension for their 289/427 cars using only the Jag IRS setup for the rear differential. They accept the Ford 289/302,351s, or FE engine setups - sticking with a more traditional configuration.

My understanding about Midstates is they offer a few more options for rear differentials both straight axle and IRS, and other engine options including some non-Ford configurations (Chevy) if absolutely desired. Midstates also seems to be proud of the fact that they will customize it and build it to your taste which is nice if you have very special requirements.

There is great feedback on both companies and their history. It's probably worth looking at both up close in person. Both are competetively priced in the market today for the roller and turnkey-minus type configurations. Or, Turnkey too for that matter.