2GM if you can find one.
Beau:I do not think that the height is a problem on those boats. The compartment is quite wide (which may be a bigger problem). The 2GM is a common replacement for these boats, but the engine is no longer mfg. The new YM series is a very nice alternative, but you may faint when you look at the price.I would look for a good used engine (Kabota, Bukh, Yanmar) and find out what is involved in the installation. If you can do it yourself then anything is possible.