Kickdown lever & output shaft bearing

Rebuilding my 72 904 trans and was wondering...

Should I replace the stock (3.8 ) kickdown lever with a 4.2 or 5.0? This is for a 350ish HP daily driver.

How can you tell if the output shaft bearing is still usable? would it be obvious if it's not? The ATSG manual only has instructions on replacement, nothing on inspection.

Thanks FABO!