727 shifter seal

No the balls dont fall out unless you are working on a cheby. The only thing that will fall out will be the accumulator piston spring.... if its even in there now. A lot of them get tossed. I know i do.
Take the linkage levers off
Pan comes off
3 screws for the filter
10 1/2" bolts come out 3 in front 3 in back and 4 where the accum. is.
Valve body comes straight down to get the shifter clear then forward for the park rod to come out...***you may have to wiggle the drive shaft back and forth to get the park pawl to engage so the rod will come out***
Be sure that the car is on jack stands. when the v.b. is out its no longer in park!

Since you have acess you could cut the seal, chisel then pry/walk out.
deep well socket to drive the new one in?