I signed up here because my younger brother just bought a 1958 B75 with a END673. Soon as he can get it transported, we'll have a look at the engine. I'm familiar with some Diesels: 1968 Hercules Multifuel in an M35 1970 Cummins NHC250 in an M818 - current project truck pictured. Lister trailer mounted 8KW generator Perkins stationary 40KW generator I'm new to Mack so I hope to find advice on it, but we don't know if it runs or not. I've advised against turning it over in case it would start and run away. It's been sitting for many years so it might be stuck. No way to know yet. Here is a picture of the customized M818 I am working on now. The entire M818 truck tractor was remanufactured in 1990. I tried 52" 16.00x20 tires on it, but I felt it was not behaving safely on the highway so I traded back for the stock setup. To get the speed up from a 52 MPH redline, I swapped the transfer case from a stock Rockwell T-138 to a T-1138 with a 0.73 OD. Redline is now 69MPH, but I like to run 60MPH to keep up with traffic. The NHC250 is at its limit on power and there isn't much to to improve that as it has no piston cooling jets. The yellow box on the side is an onboard 6KW Diesel generator. More has been done there for that enclosure. It's from a lighting trailer, so the enclosure is being adapted to this application. The body on back is from an M109 2.5 ton truck. It has a 2500# lift gate on the back but it can't be seen in the picture. The electrical system is 24V and I added a 12/24 battery equalizer to power any 12V accessories. There is also a RADAR set, two 9000 BTU military a/c units, and collapsible 27 FT antenna mast to be installed after the rear body gets some sheet metal work. The cab and chassis are in green CARC. I would like to air condition the cab. It's in Texas so it does not get driven much. I drove it from Illinois to Texas in January 2010. That was an interesting trip, cold starting out. Texas heat, plus the heat coming through the cab from the engine, makes it a little unpleasant. It will take about 30,000 BTU to cool that cab.