'51 331 Hemi with 904 auto trans

Early hemi engines usually have the bellhousing built onto the back of the block. Only $1,000 bux for that one.

Nothing is a direct bolt on other than a cast iron TF. Adapters are made, looks like they don't do 904, just 727 and 518.

Hothemiheads website below

https://www.hothemiheads.com/transmission_adapters/