I have a 1950 flathead. I want to use the ford t5 I have from a mustang. What is the cheapest way to adapt this.
Depends on the bell housing you're using. The '49- '53 Ford/'51-'53 Mercury 4-bolt bells can use a 1" adapter.
Yes, Buy you a 1" thick 10 X 10 piece of 6061 Aluminum and make it yourself. Or source a buddy with a lathe that will swing the 10 X 10 plate or a Mill. I can send you a drawing that was shared with me for the Plate. It's actually a pretty straight forward piece.
http://www.wilcap.com/flathead.html I bought mine from Wilcap. "Cheap" and "flathead" are terms rarely used in one sentence. I bought the Wilcap because I wanted the best.
Which ever you use check the concentric of the locating bore and flatness once installed. I had a trans issue and thought I had assembled the trans wrong so replaced with brand new untouched by me and am at the start of the same trans issue and suspect the adapter.
If you have the stamped steel 49/53 Flathead car bellhousing and a Ford T 5 this is the one that Billy was linking to.