Early (65) Torqueflite Questions

I am rebuilding a 65 vintage Torqueflite for a friends 64 belvedere and have a few questions...

1 - the 65 and 66 rear pump slip yoke autos used an internal seal on the output shaft and a grease lubricated yoke with a vent hole. Can I leave the internal seal off the output shaft and run a conventional atf lubed slip yoke?

2 - are all cable shift valve bodies the same, or are push button ones different from cable column and console ones?

3 - has anyone done the conversion to larger late style reaction and input shafts, and if so is there a preferred date range of parts to use? I assume the pump, reaction shaft and input shaft all get changed?

Any other advice on building a percormance 65 vintage torqueflite? The intention is to have a slip yoke button shifted trans.

Thanks!