I have a 69 factory 383/727 sport satellite purchased bone stock from original owners in 1976; so all work or mods since then, were done by/for me, so no mysteries involved. In 1979 I took the car off the road to have it painted, rebuilt motor and trans with modifications for performance. At that same time a Cheetah full manual reverse valve body (P,R,N,1,2,3) was installed. I left the factory center console shifter in place. With the reverse pattern valve body and shifting away from neutral, it performed good enough for me, as I didn’t want to bugger up the console on fit in a slap style race shifter. I didn’t mind the full manual function, as I only drove it about 200 miles a year, if that. Here’s where my problem is. When we did the valve body install, there was quite a bit of finagling of the trans linkage to allow enough travel to get to 3rd gear with the shifter. I remember the trans guy saying I had just enough length to clamp the shift rod down to get all gear positions to work. Park, neutral, 1, and 2 were no issue, and 3rd was fine, although the shifter was as far back against the console as it could go, but it worked fine for 40 years. Forgot to mention that of course all the kickdown linkage under the hood was disconnected, and only the original gear selector linkage under the car at the transmission is used for the manual shifting. Long way to get to the problem, but figure too much information is better than not enough, so last week I had my car at a shop for some minor maintenance work and asked to check ATF leak, which was determined to be the lip seal on the speedometer gear adapter. Because he needed to free up his lift, we decided I would order the new seal kit, and install another time. He also mentioned he noticed the shift linkage under the car was “flopping” around and adjusted the rod per the factory manual. Well, I brain farted, and should have realized that was opposite of what I need for my gear selection. As soon as I picked up the car, I realized that the shifter felt funny, and getting reverse wasn’t normal, but worked pulling a bit further towards neutral. He was in a hurry so I figured I would take it home and deal with it later. It was when I was heading home that I realized that pulling back to get third gear didn’t work. Fortunately I only had to go a couple miles and traffic wasn’t too bad, so most of the drive was in second gear, but still about 3800 rpm just to go at a normal speed around 35-40 mph. Got it home, and got the car up on jack stands, crawled under and reversed his adjustment, which had the lower rod pulled towards front of car through the swivel and locked with about 3/4” of the rod end exposed past the swivel. I remember that was the area of finagling years ago and that there was barely enough of the lower rod in the clamping area to lock it in, and have my transmission operate as intended. I figured I could just loosen the nut, with car in park, and pull it back towards the rear of the trans, to about where I remember it being. I had my wife try moving the shifter in the car while I observed from below. Everything functioned normally, with her getting the click between everything until trying to get third, furthest position back on the console. It gets a spongy feel of resistance there, and just doesn’t want to click. It appears everything underneath is ok, but is there any way that I can confirm that? Will I screw something up if I take that rod out of the gear selector coming out of the trans, and move the selector itself by hand to check it. Will it click between positions down there, or is it strictly a position location for each gear selection? I thought about something off up at the shifter inside car, but don’t want to try that, as it was never part of the adjustment process before, so I don’t think my problem is there. Finally, all of this has been with the car up off wheels, and based on just the in car shifter feel, which feels normal until trying to get it to that last 3rd gear position. Would getting the car down and running change anything? I know I need to add some ATF once I lower it and get it running, just trying to get everything fixed while it’s in the air, as it’s a process to go through that, but if necessary, I’ll have to. Any help with this is appreciated. I’ve tried multiple adjustments on the lower linkage, with similar results; everything feels right until third gear. Thanks to all in advance.