parts interchanging? D4 7u

Looking at the parts manual most parts should swap straight over including the pony. The tracks too provided they are the same length. Are both 5 roller track frames and heavy duty type? Others will know more than I but I recently re-built a 58 7U using parts from 2 other 7U's that were much much older and apart from some cosmetic aspects where Cat had improved engineerings etc, all parts were a straight swap.

I have not seen it yet. the main part I want is the pony motor in case mine gives trouble. Thanks

If you don't live in extreme cold and you use your D4 regular you might consider putting direct start on it. A MT 40 starter cost about $300. A lot cheaper then rebuilding a pony. It's so nice to get on and push a button and its running.

If he decides to go direct electric start, he'll have to drill the bellhousing for the starter. A 1951 D4/7U did not have the bellhousing drilled and covered with a plate yet from the factory.

He is correct I would have to drill my bell housing. I really like the pony. Mine starts fast and I don't think I could drill the hole in the correct location. The starter you are talking about Will it come with the correct end for $300? Thanks