I went out and took pictures of my 500b with a 201 out of a 660 combine. Added a inch to side rails and hood. Made a hole in hood for exhaust. Used the three bolt starter. I used the 164 timing cover and it had the smaller impeller on the water pump. I should have used a 188 timing cover with the larger impeller because on a hot day it will run about 220 degrees and kick out some coolant. The radiator has had some cooling tubes blocked for repairs. A easy conversion. I have used this tractor for several years and it is a power house. Will pull my M&W 10 wheel high capacity rake in 4th direct but will heat like it is. Need to replace radiator. I have put a electric fan pusher on the front of radiator but didn't really help much. I hope this helps.