In talking with the repair shop, I have found out that this 1650 diesel does not have its original block but has its original head.  The tractor serial number is 187 870-465 (1967 model year).  The head has a casting number of 223102 and is stamped with the year 1967 (which matches the year of the tractor).  The block has casting numbers of 221320, 163371A and 137 and has a serial number of 128371 (the fuel tank bracket is not off so I do not know the year stamp).  The questions the shop has are:
Are the head and block compatable, and
What should the sleeve projection be from the face of the block?
Thank you, again, for assisting me with this.