Here is a copy paste for anyone searching PTO speed that comes up with this thread (and can't see the reference drawings). Note it was for the deuce with Allison but also applies to the 939 series w/Allison. Re the PTO speed and my search:
It ranged from a reduction to an overdrive so I went and counted the teeth of the PTO. The tranny mesh gear is 25 tooth, which drives an intermediate shaft that has 14 teeth, driving the output shaft with 29 teeth. Thus there are 2 ratios, that of the transmission to drive gear and the intermediate shaft to the output shaft.
For every engine revolution, on the 939 series, 64 teeth will pass and on the M35A3, 55 teeth will pass, both contacting the 25 tooth engagement gear. So at 1000 engine rpm, the larger Allison will turn the intermediate shaft at a ratio of 64/25 or 2708 rpm. Then the intermediate gear reduces the speed on the output shaft at the ratio of 14/29 or 1307 rpm.
On the A3 with 55 teeth and 1000 engine rpm, the intermediate shaft will turn 55/25 or 2200 rpm and the output will turn 14/29 of that, or 1062 rpm PTO output.
Thus the Chelsea that I have, when running the engine at 1000 rpm on either vehicle, will turn the output of the PTO on the M939 series at 1307 rpm and 1062 rpm PTO output rpm on the M35A3. Thus both are overdrives, not reductions. Sizing the pump can be made from these rpm's
Note that the "tranny mesh gear" is the one on the PTO (25 teeth). The Deuce (A3) tranny gear is 55 teeth and the 939 series is 64 (if not clear from above).