I'm putting a Mitchell overdrive in my 34 coupe. It has a 4.11 rear end. When the overdrive arrived it came with a 6-10 spline coupler. My pinion is a six spline so I needed the 6-6 spline coupler. Is six spline correct for a 34\v-8? Or has someone changed it? Don't know what years used six and which ones used ten. I have searched several sites and have mixed results. Thanks, Steve