The 307 and the 308 are input shaft bearings. Keep in mind my car is an old drag car so everything on my car is '66/'67 vintage. My transmission has a 307 Hemi bearing retainer. It works well, but I always wonder about going with a 308. The case is an original '66 case that currently has an 18 spline slickshift gearset. I want to drive on the street so when I decided to redo my rear wheel openings I really tore into the car. Now I am building a new fully synchro 18 spline for the street with later style synchros. I'm also going to replace the spool with a Detroit Locker. The driveshaft is a very nicely done custom job. I'm guessing it was originally a truck or C-body shaft that has been cut and rebalanced. U-joints are 7290s, and they work great. Big slip yoke, and the 3rd member is a 742 big yoke from an old altered wheelbase car.