From Novak's site I had to look it up and read it again. About to order parts for my t18 so not too much help yet on the install Bearing Retainer Modification For the first step the services of a machinist may be recommended. The front bearing retainer from the Ford transmission is removed and simply machined down around the large diameter to where it will be a .005" slip-fit into the bearing retainer hole in the back of the GM bellhousing. Take an accurate measurement (and with the proper tools -- calipers work best) from the hole in the bellhousing before doing this. The small diameter of the Ford bearing retainer is also machined down so it will slip-fit the GM clutch release bearing. Next, the retainer is then shortened by 7/16”. Following this is some fairly straightforward work on the Ford transmission case.