Did some TE-20’s have Z129 engines in them? April 11, 2016.
TE and TO-20 tractors were all originally equipped with Continental Z120 engines. If you have located a TE-20 with a Z129 engine it is not the original engine. Apparently someone has installed a Z129 engine in that TE-20.
First check to make sure the engine in the TE-20 is really a Z129 engine. Continental modified the original Z120 tooling to make the Z129 engine. When the stock of Z120 blocks was exhausted Continental used Z129 castings to make Z120 engines. These Z129 casting Z120 engines have the bosses for the side mounted oil filter, and the bosses for the TO-30 generator mount on the castings, but those bosses were not drilled and finished. The blocks were finished as Z120 engines. If the Z129 engine on the TE-20 you are considering has the side mounted oil filter, and the bosses for the generator drilled and tapped for the TO-30 generator mount you have a Z129 block.
If that is the case, all you have to do is install that Z129 block in your TO-30. If you choose to use the crankshaft that is in this new Z129 engine, be sure to check the casting numbers to be sure it is a Z129 crankshaft. The Z120 crankshaft can be installed in the Z129 block but it is not the same, the Z120 block has a shorter stroke.
Do not use the cylinder head on the new Z129 engine unless you check to make sure it is really a Z129 head. The Z120 cylinder head will fit on the Z129 block, however there is a difference between the two cylinder heads. The obvious difference is the Z120 cylinder head has intake and exhaust valves of the same diameter. The exhaust valves on the Z129 block are bigger around, have a larger diameter, than the intake valves.
If you install the new Z129 block in your TO-30 you do not need to install the extra engine/front end support braces used on the TE-20.
Do not scrap your old Z129 block. It is very likely the block can be repaired by bolting or stitching. These blocks have core value so you should be able to sell it as a core to be rebuilt by someone else.