I have a 24.5 hp Walker mower with a liquid cooled Kubota engine. looking to replace the engine with the 752 Kubota, but I am told you have to take a bunch of the new parts off and replace them with the parts off the old engine the 750.... like the starter alternator etc. I would like to know why. anybody? The other option is to rebuild but a short block is not available. what about the other parts?