I bought a '66 442 with no trans or engine. It was a Jetaway car. It did come with the two piece driveshaft with rubber holding the two ends together. Are they junk and unfit for hi-perf use? I'm going to install a Muncie. Is the driveshaft the same length for Jetaway and Muncie 4 speed? Is it unlikely it would pass a balance or runout test?

 

Yes, the driveshaft length is the same for Jetaway and Muncie. The factory used the rubber-damped driveshafts on AT cars only, not on MT cars.