I am doing a 1928 dump truck right now that came with a 4 cylinder but some idiot shoe horned in a 216. Of course the back 10 inches of the engine is through the firewall and beside the foot feed pedal. After checking out options I think the 153ci four used in early Chevy II's will be an ideal fit. The Chevy II and mail truck engines are getting scarce so I'm using the marine version, a Mercruiser 2.5. Had no luck finding a car type exhaust manifold so making up a shorty style header. The Mercruiser has 120hp compared to a 194's 50hp, a 216's 80hp and is as much as most of the later 235's. It's a very compact engine and will have 5" to spare in length over the original 1928 four banger. I made a very simple 1928 transmission to 1955 and newer bell housing adapter and using the straight bolt on cast iron early V8 truck bell housing; the one the starter mounts to. The Chassis Engineering flathead Ford type motor mounts will be cheap and easy to fab frame mount brackets. The four banger gives plenty of room plus has more power and FIVE main bearings. Entire project should come in at around a grand including the engine purchase. Will snap some pics if you're interested. Good luck with your's.

Evan