Technical 63 Impala 3 speed trans stuck in gear

Good to hear that you got it done.

 

I'm here late so forgive the "I already did that's!" Getting the side cover back on can be very frustrating as you well know. The funny thing is, now that you've done it, you are near an expert.
I was helping rebuild a Muncie 319 with a friend (just like yours only it has an overdrive attached to the back, your model is a Muncie 318). I was promising myself that I would be teaching a man to fish so I was encouraging, motivating, and supportive of his efforts. We were on the home stretch and you guessed it, the last step was getting the side cover on properly. Long day, probably not enough water, hot, tired, frustration setting in. He asked me to set the side cover on and I then asked him to check his alignment and try again. It went on and he was ecstatic. I then asked him to take it off and do it again. He did it.
Epilog:
My white gloves never came off.
Bonus:
I saw a post (not on this forum) where he was giving someone transmission advice.
Tons of great advice on the HAMB with patient teachers, happy reading!

 

So what happened was I didn’t have adequate light to see if the forks were engaging in the proper spots. I should have never done it on sloped driveway because the 1/R sliding gear was sliding rearward as I’m getting it between the shift fork. I needed more hands as the gasket had to stay in place while using one hand to slide the gear while the other is inserting bolt. The side cover isn’t easy to hold with one hand on a slope. This all started because I dropped the stupid cap for gear oil in the fill hole. Murphys law happened that time. I can attest that anything and everything that went and could go wrong happened during this******* job. More on that on another thread.
Thanks again gentlemen