[Clark Rodgers]

I hope I can clear up a little confusion that your friend is causing.

The 9in. is either a 28 spline or 31, this is the number of splines on the two axles where they connect to the center section. Your motor might be a little strong for the 28 spline and the 31 would be better, but Ford's 9in. is one of the strongest ever built with or without the 31 spline. You can check with alot of chevy racing guys they know this rearend can't be beat and they have them installed in their cars.