Think about parts availability. Especially for any old or major components that aren't available anymore. Whereas, these days, the Ford 9 inch is on par with the Chevy small block in the 70's, 80's and 90's. Or the LS today. Everybody makes plenty of parts for them. I thought about adding a Jag rear end in one of my projects. Firstly, they were difficult to find and when I did, the seller thought they had gold.
