Anybody with an old Cragar Catalog to check a part #

I have what I believe to be a Cragar trans adapter with a 603 part number. I am sure its to a old Ford trans but not sure what motor it bolts to. Any help very much appreciated

 

Cragar #603
1958-61 Mercury (all except 312) to 32-48 ford trans and 39-50 mercury trans

 

7 minutes for an answer, not bad. Bob

 

Wow, that was fast. Can anybody fill me in on the popularity of the Mercury motors? I have no clue and was wondering if the adaptor is a hard sell or a good market item as I plan to sell it. Thanks Dragnut!