the main things on engine replacement
1 - engine crankshaft length and diameter
2 - fuel pump or gravity flow
3 - size of alternator on original compared to the new engine (electric PTO requires more amps)
4 - is the mounting hole pattern on a 33 series the same as a 31 series
5 - also the exhaust muffler
1 - engine crankshaft length and diameter
2 - fuel pump or gravity flow
3 - size of alternator on original compared to the new engine (electric PTO requires more amps)
4 - is the mounting hole pattern on a 33 series the same as a 31 series
5 - also the exhaust muffler