Trans Decoding help

I have a 1987 Dodge Ramcharger 2Wheel drive automatic 318 V8.

I am having a issue with 2nd gear just not being there, which come to find out is the common problem in these trucks.

Anyway Im wanting to get it rebuilt but I don't know if it is the A998 or the A999. I was hoping some of you could help identify the trans by the number.

PK4431556 9265 7632