Block interchange 9U and Late 8T oil clutch

I think you are correct, there has to be something different in that area to allow oil flow. Even if it was just the rear main cap, having to swap that out should require line boring to insure correct alignment and tolerances.

Should be lots of good blocks available. Some of the problems that plague other engines like liner counterbore erosion were apparently pretty rare in the 1940's and 1950's engines.

Due to the oil clutch oil supply coming from the engine oil pump to the clutch the engines are not interchangeable.

The d6-9u block motor 9u 1 to 9u11928-- 4f7054 block
the 8t block motor 8t1 to 8t11251---4f7054 block
in micro fisch

my 9u is serial number 9u27xxx. What blocks would interchange with it?

The d6 serie 20a and maybe 10a should be correct

Any oil clutch 9U or 8U tractor has the correct block. Part number is 1H5655, casting number is 1H5652. Oil clutch came standard after 9U13263, though there were probably plenty earlier model tractors that were converted as well.

Some older D318's had a block casting number 4F6480. Part number is usually something similar just a few numbers higher. I got that number off an engine I thought came out of a 9u tractor, but who knows where it really came from since I couldn't find a serial number on it today. I might be looking at an oddball, Not sure at what machine serial number that block was replaced by the newer casting, because my parts book starts at 13263. I don't know what the differences might be between the two castings, but I seriously doubt you couldn't swap whole engines. Maybe not good to mix and match internal parts though?????

Unfortunately it looks like we’re out of luck this time Catboy. Good luck with your quest.