76 /302/ C4 trans issue

[Btweb76]

Greetings,
My 1976 Bronco was having some shifting issues, (C4 Automatic Trans) shifting a little hard and clunky. It was also leaking a bit, shocking I know. I took it to the shop to get new tires and have them tighten some stuff up, take care of a few things and to check the transmission. Anyhow, they took care of most of the leaks and showed my a small part (looked like a tiny cylindrical half inch or so spacer) from the transmission and said that was the issue. I had a lot going on at the time and it seemed to be running ok. But don’t really get to drive it much winter came and so it sat for a bit. Drove it about 10-20 miles. Transmission was still a bit rough. Then it wouldn’t real shift into any gear. Was able to get it in the driveway and checked the fluid and they had overfilled the fluid.
Anyhow, I’ve drained it, replaced the filter, vacuum regulator (made sure pin was there) refilled to a proper level. Won’t shift into any gear.

Any suggestions on what to try next?

Also, any recommendations for good reasonable transmission repair folks in the Denver area?

Thanks for any insight or pointers!

 

[thegreatjustino]

@Viperwolf1 is in Aurora and is the resident C4 genius

 

[DirtDonk]

When you checked the transmission fluid level, was it in the correct shift position? Most are done in park with the engine idling, but I can’t remember if the C4 was the same way.
If you did it with the engine off however, that might explain the high fluid level.
Does it list on our dip sticks how to check?