Advance Adapters sells the Ranger Torque splitter. It gows in front of the transmission, between it and the bellhousing. Your speedo and park brake remain intact. I just put one in my 58 2 ton. I am running a 327 that was in the truck when I got it. I dropped from 3600rpm @ 60 mph down to just under 3000rpm.
That said, mine is an older cast iron one (no idea how old, or what shape the insides are in, I just put it in along with the trans that was attached when I bough it!) Mine added some noise and vibration but, I believe a lt of the noise is the transmission. One of these days, I will pull it back out an pull it apart to replace bearings in both trans and OD. We hauled our 35' vintage travel trailer about 7 hours away in July with it and had no problems. We are heading a couple hours north of here with it later this week.
https://www.advanceadapters.com/pro...overdrive-27-with-a-4686-retainer-index/
