Cummins is longer and heavier, and been done many times over. Really can't see it being a problem.

 

I'm sure it can be done. However, a Cummins is longer but not as wide an engine. It's also much heavier than any engine the truck was designed for.

 

You would be surprised how wide the cummins is with its jewelry. The V10 is a lengthened 360.

I have a 74 parts truck that the Cummins has been removed from. Also a 2wd ramcharger project with a cummins sitting in it. Its just Lego and little bit of cut'n'paste. The 2ndgen rad is going to be installed in one of my 75-90 rad supports, haven't decided which one yet.