I have 2 650 4wd tractors. One has 900 hrs and a blown engine the other with unknown hrs and a good running engine. The trans shifts kind of rough and the 3 pt hitch has inconsistence operation. My plan is to use the low hour transmission and 3 pt with the good engine. I am not sure yet if I will attach the front end of the running tractor to the low hour rear end or if I will pull the engine . The engine is already out of the blown one. I am looking for advice on what method I should use and also if there are any seals that would be good to replace since I will be in fairly deep?