well, the 2.8L is a 10 spline clutch...23 spline is for the 4 cylinder...but I did find one at summit for $130ish which I'll get when I tear the engine down for a rebuild...as for what the project is, I hate to dissapoint you but the only mustang II part I'm using is the clutch...its a '66 coupe with a '93 Taurus SHO 3.2L v6 converted to RWD using an aerostar bellhousing, adapter plate, mustang II clutch, SHO pressure plate and flywheel and a 302 pilot bushing that has been turned down to fit the SHO crank...its a pain in the ass to track down this clutch disc though...finally found a stock one locally today for $25, which will do until the engine build