Well here's some bad news. Well not bad but it doesn't help. I am pretty sure those numbers have nothing to do with the converter. The RG 130 means ring gear 130 teeth.
Pioneer ring gear with use on a 1968 727 part number is FRG130T.
Pioneer Inc. - Flywheel Ring Gear
Part # FRG130T
UPC: 727993015872
Without High Performance Engine
A727 Automatic Transmission
131 Teeth
OE Number: 1941648