I have an '86 non-turbo manual tranny and I'm swapping my 4-bolt hubs to 5-bolt hubs for race/autocross reasons. Are there any differences in the driveaxles. When I'm replacing the 5-bolt hub there is lots of play. Then I notice there is a stainless steel raised portion of the driveaxle just inside of the outer spline section where the hub would go. Are there any differences in driveaxles from manual/non-turbo 2nd generation Rx-7's. Or, is it just a matter of adjusting the length of the driveaxle/boots. Any help would be appreciated.