My search for a shorty D100 is over

TT5.9mag said
Critical speed, schmitical schpeed
Bonneville guys will get that. New 5 inch aluminum driveshaft from inland empire driveline is installed. The D100 is officially V8 powered. View attachment 1716387013 View attachment 1716387014

Tell me more about that driveshaft. 5" diameter, what length? I was looking at a 4" which would be good for 7400 but 5" would be better for OD.