Anyone out there know if it's possible to replace a 1920 Maxwell motor with a later (1925-6), 4 cyl motor? I've just about given up on my motor. It did run OK. Now, It never fires all cylinders at once alternating between them. If I disconnect #3, #4 will fire. Have replaced timing gears, valves, adjusted valves to spec, distributors (now trying electronic),dist caps, plugs, plug wires,carburetor. Gets 50 lbs compression in all cylinders. Out of desperation, Have tried every firing combination but still does best with 1-3-4-2 (which is not good)