Aluminum R5 and P7 heads.

Wow! Well, that is certainly interesting!
IDK what that would take $$$ wise to finish, but that would be a fun and interesting project to stab in any old and light car.

The seller said he wanted to put it in a ‘36 Dodge (?) which would be a scream and a half. Probably got tired of hunting parts and paying a lot of money to get no where.