The 30 has a 162 cu in Continental whereas the 22's have a 124 cu in. For your info reserves, the blocks are identical in the 22 (124), the 101 Junior (140 or 162 cu in) and also the 30's. The earlier 101 Junior's had the 140, then in the later versions they had the 162.
The 30 series, I believe, replaced the 101 Jr with the updated 5 speed and hydraulic cultivator lift. The point being, if a 101 Jr motor is available, you may get lucky and find an identical 162 or at least a 140 to slip in place of your motor.
Another tid bit to remember, the 162 can be bored to a maximum of .120 over, if you ever need to know that anyway...and assumption (which agreeably is seldom a good thing) tells you there is probably similar room for expansion of the cylinders in the 124 and 140 also. I have never checked the crank throw differences to commit to memory, so I have no input on that.