A998 Trans in '66 Dart

The 999 I'm going to put in my 65 Barracuda must be a 80's model. My book doesn't list it, and the number is beyond any listed here previously. I've Googled it to death, but must be wording the search wrong! :realcrazy: It's P4295887 7966 5768. It's a lockup for sure, and I'm hoping it's the low 1st gear.