Picked this custom adapter up in a bundled purchase. From measurements it appears to fit GM to a Ford tranny. My info is limited. My transdapt book shows the bolt patterns to be GM and Ford Ranchero / Falcon?? Have a look and see what you think.
200 and 250 have different bellhousing bolt patterns. The 250 uses the same bolt pattern as the sbf....
Also, that would be 144, 170, and 200, only to 1966, with the bellhousing that I showed. That one is for an 8-1/2" clutch. Up to 1966, the 200 had both the 8-1/2" and 9" clutch bell patterns on the block. After that, only the 9" pattern. The 9' clutch bell can be distinguished by the number of bolts that hold the starter on. 9" has two. 8-1/2" has three.