Hot Rods Hemi ID

Need help with this hemi cant find the exact numbers of what it is

 

Although stamped C55, which may lead some to conclude it is a 1955 Chrysler, the casting number says 51-53 331.
The intake is typical of the 51-53 2bbl.

 

Much appreciated

 

Judging by the end of the crank. I am gonna assume its a marine hemi

 

solid front heads & the thermostat opening in the intake is blocked off....

 

How about a photo of the rear of the block.....

Ray

 

Its the extended bellhousing block.