passion performance 5 speed

I have thought about the Passon 5 speed and it is going to be great for the guys that don't want to cut up their cars. Mine is a 68' Valiant and I have decided to go with a T-56 Magnum trans. Since I'm starting from scratch the cost is not much more if you use all new parts. About the only thing is I'll probably have to use a Hyd. clutch system. With a Passon 5 speed you can use the stock linkage. But I want to be able to use dragstrip rear gears and still be able to cruise 80 mph on the highway with the .5 overdrive.