Does anyone have the bolt pattern for where the bell housing bolts to the engine block on a D315?  I am trying to use the engine for a repower and need the dimensions to build an adapter. 

could they be a SAE flange pattern it would make sense as it would allow easy fitment to many applications which cat always did with their diesels. to my knowledge they always had them able to be used as stationary engines. if you got the installation guide or service manual for the 315 industrial or marine engine the info might be in there.

if you had an engine you could easily get the pattern using poster card stock, couple of light dabs of grease or double sided tape and a mini ballpien hammer.
the grease holds it in place and you gently tap along the outer egde using the ball face to mark the pattern and cut the shape then press and wriggle the hammer to find and cut ot the bolt holes.the same method can be used to make paper gaskets.