TO30 Block shot. Can TO20 engine be used instead?

[TO 30 Steve]

I have a TO30 that threw a rod through the right side of the block. Took out the distributor. Laying on the ground ten feet away from the tractor. The engine wouldn't run anymore. Would be funny if you didn't love old U.S. iron. So I bought an old TO20 that was advertised as being in running condition. My question is: Can I swap the TO20 engine into the TO30? It looks the same. The TO30 has one more gear than the TO20 but that shouldn't matter. I'm just looking to get the old grey horse back to working. The old TO20 is not worth restoring. Going to pick her bones and sell the rest. I've rebuilt a TO30 engine and two 8N engines so far. I'm in N. Georgia, so anyone who needs TO20 parts can call me. Would love to see her live on in other tractors.