Just a thought -- why not consider a gear vendors overdrive unit?. This will eimentate, clutch, presure plate, throw out bearing, linkage, and shifter location issues. The initial cost may seem high, but should be compareable to the cost of a 5 or 6 speed manual that will handle the power and torgue. Plus when you sell the car you can remoce the unit and drive shaft -- and use it in another vehicle.
