Quoting the Buick Bomb Site catalog on 63 Specials http://www.buickbombsight.org/sky6.html "Hypoid gears, semi-floating. Gear ratios: w/3-speed synchromesh: 3.23 to 1; w/4-speed synchromesh" 3.36 to 1; Skylark w/Dual-Path Turbine Drive: 3.36 to 1; Special with Dual-Path Turbine Drive: 3.08 to 1. Rear wheel bearings permanently lubricated." Now according to the site a Skylark came std with the V8 while the Special ( which I have) came with the V6 . Soon to be a 215 V8 Using a handy dandy calculator I found @ http://ultimategto.com/art29.htm I calculated my speed @ 3000rpm with the 3.08 rear end , 1:1 final drive and 175/80R13 as being 69 mph ( though I see 60mph @ 3000RPM , but who knows with these speedos) with the 3.36 being 63 mph. My question is why did the V8 come with the lower geared rear end . Normal think would be that bigger displacement => abiility to turn lower revs on the HiWay. Was it because the Odd Fire was really rough at higher revs ? or Did they want the V8, since it is inherently smoother @ higher revs, to have more giddy up when passing ?:3gears: Enquiring minds have to ask ? . Thanks Justin
Justin, Don't know for sure how tall the original equipment tires were on your Skylark, but 175/80-13's are 24" tall overall. This would affect the final drive ratio. The road test of a 63 Skylark ragtop with the 215 V8, and 3.36:1 rear, says 20 MPH/1000 RPM. Another road test of a Skylark with the 300 V-8, and 3.08 rear, says 24 MPH/1000 RPM.