The front of the LoMax case provides bolt patterns for the common GM figure-eight pattern and the later round six-bolt pattern. The round pattern is a dual form allowing higher positioning of the front output shaft and improved ground clearance. Another use for the LoMax case is for, strangely enough, stock gears. The round pattern GM205 case is as rare as hen's teeth, and the LoMax case is a direct swap. If you have a figure-eight case and are looking for an easy swap to a round-pattern application, the LoMax case can be used with stock NP205 gears.