it was a 318 AC car with an 8 3/4 and 2.91 gear set but open. This is the one I stole it the 489 center from and threw a spool (no bearing or even pinion seal change!) in for the road trip up to Mopars in the Park the first time. Then last year I used 3.23 SG I bought here. This year, it will be the 3.91SG that is in the car. Taller tire and plans for 2 lane highway this year