190 2 pinion vs 190 4 pinion 200 rear end

what 190's have a 4 pinion rear end? and will they inter change with a 2 pinion. i do know that you can not take a 4 pinion out of a 200 and put it in a early 190. so is the later 190xt series 3 use the same 4 pinion as the 200 or is it different 

Small 2 3/4" axles (prior to s/n 9001) were all 2-pinion from the factory and even after the driveline update kit. All other 190's and 190XT's from s/n 9001 up to 23000 were still 2-pinion differentials and had the larger 3 1/4" axles. At s/n 23001 ( series 3) the 4-pinion differential was introduced, which was December of 1968, so just say from 1969 onward they were all 4-pinion diffs. So, by that time, there were enough 2-pinion tractors that had failed, they were getting repaired with 4-pinion kits which required a new ring and pinion because the ring gear I.D. was milled out larger than a 2-pinion ring gear. A 200 and 7000 differential is essentially the same as any 190XT 4-pinion diff. I would guess there could be as many as 50% of the 190XT's that have been repaired to 4-pinion diffs. If the tractor came from an area where there was moldboard plowing done, it has probably been changed to 4-pinion because the 2-pinion didn't hold up very well.  2-pinions hold up to 1200 HP if the pin is needled/hardened and the backside of the side gears are machined to accept flat roller brgs. EITHER DIFFERENTIAL MUST HAVE THE OIL LEVEL RAISED TO FLOOD THE DIFF TO HAVE ACCEPTABLE LIFE.

They are either finding the correct "4-pinion" ring gear/ring and pinion set from a 190XT that had a 4-pinion in it, or milling the hole in their 2-pinion ring gear to be able to slide onto the 4-pinion diff case.

Can anybody verify if the later d19 differential side gears were 23 spline or 25.

Thank you in advance

Ok so should be 25 spline. I looked the part up on a parts house and they said 23 spline so was wondering.