Mark was correct in saying it was only offered with a rear gear case. That is all that is listed on quickserve. It appears that the front and back of the block is the same as a "normal" 4bt. However, that means nothing. Maybe some things could be swapped but more than likely not. There would be a lot of work involved if its even possible.
I have two inline pumped, turbocharged, 4 cylinder b series engines sitting in my shop right now and I can tell you they certainly were NOT $600 so I understand your interest in this one LOL