Not sure the press fit is all that important, all of mine went right in. The torque on the nut is what ever that size thread can take, look up bolt torque spec's and find your size of bolt. I seem to remember just using a long ratchet and socket. On my drag link, I went with the later model sealed type with a custom made threaded rod to allow for a dead straight center steering wheel. The stud will drag across the axle if you do not shorten it up, I used a 4" grinder to take some threads off.
The bores of the arms are hour-glass shaped, so a true tight fit nots going to happen, just the middle portion fits tight. Just make sure the top and bottom surface of the arms are flat so the ball seats and the washer and nut fit flat.
Before installing them, chuck the ball portion in a drill press or hand drill to spin them. Get some fine grade lapping compound and while spinning the ball, lap the cups to the ball. When I first installed mine, it was really hard to steer, the cups kept digging into the balls. I pulled them all back out and lapped them to each other, it made a big difference in how it steered. No special tools required, wear gloves, as it gets messy, and it didn't take all that long to to do. You will feel when they start to get smoothed and lapped together.
Joe
