A common complaint is inability to find reverse and fifth gear easily. I had that problem with the Fatrat yesterday (both gears were accessible with this gearbox in the rat). I worked the shifter all the way to the right looking for reasons I couldn't find those two gears and heard a definitely "clunk" sound and it sounded like it was coming from the tunnel. I pulled up the hand brake mechanism and saw I had installed too long of a seat belt bolt and the shift rod was hitting the nose of the bolt. Ha! A shorter bolt solved the problem.....not. Still had the sound of the shift rod hitting something. Popped off the rubber access plug behind the emergency brake handle and saw the rod was hitting the side wall of the tunnel on the driver side. Must have been doing this with the previous engine/gearbox as it was easy to see where the paint had been worn off the tunnel wall. Went under the car and adjusted the two bolt linkage between the shift rod and the lollipop to bias the shift rod more to the right so it won't hit the tunnel wall. Just backing out of the garage showed reverse was easy to get now. Also, make sure the lollipop to trans shifter bolt has no lateral play...I tighten down that spring washered bolt to the point it swivels with a little resistance but there is no side to side play. The point of all this is that, as noted in many previous threads, failure to find reverse and 5th or not easy to get them is usually a linkage adjustment but most of those threads never really got into what you are looking for in adjustment.