Matt, I also have a 1948 EG. The original engine is a EN 330 cu. in. Continental. If the tank you see is behind the passenger side running board, it is a vacuum tank. Mine is a tractor and has the trailer brake valve on the steering column. Mine also has hydraulic brakes with a hydrovac. Mine had a cracked block when I bought it and I looked everywhere for a block to no avail. I had mine repaired at a pretty big cost. Naturally, after I had mine fixed, they started turning up all over. I believe Continental calls them a M330, and I've seen them in a Gallion road grader, Bucyrus Erie dragline, Buffalo Springfield roller, and several stationary applications, like welders, compressors, and such. I'm no expert on 48 EG's, but I did take mine down to a bare frame and started from there. I haven't touched it in 3 years due to health and financial situations. (those 2 things seem to go hand in hand!) Feel free to contact me with any questions you may have. Tom