TH350 unidentified part

[Albatross1953]

I'm rebuilding a 1972 TH350. It's been a few decades since I had one apart. There is a weird looking clip that was lying inside behind the read clutch pack. I don't see it in any diagrams. Pic is attached. There were also 3 little black balls (approx 1/4") rolling around. They look a little large for valve body check balls. Can anybody point me in the right direction.

 

[Indycars]

Since your are rebuilding your trans, have you thought about going to an overdrive trans like the 200-4R. It's over drive is 0.67:1 . Same size and uses the same driveshaft. The mount location is different.

 

[Albatross1953]

Since your are rebuilding your trans, have you thought about going to an overdrive trans like the 200-4R. It's over drive is 0.67:1 . Same size and uses the same driveshaft. The mount location is different.

I'm doing it for a friend. He's rebuilding a '72 Skylark from the frame up.