Things just got weird

Forgive my ignorance here. This is my first 4-speed Mopar. I have what I believe is a fairly rare a-body 18 spline 4-speed. I installed an old-school Mr.Gasket shifter from the 60's or 70's. Really heavy duty feeling shifter. Anyways, the weird thing is reverse is not to the left and up. It is to the way left and down just a hair. That is the only way the car goes into reverse. From what I can tell all the other gears work normally. I have only driven it around the block once because I don't have the title. I did manage to get it into third. I bought the Trans seperate from the car because that is the Trans it was supposed to have being a BH29H car. So, either I somehow hooked this shifter up wrong or the Trans is configured differently. Any thoughts?