Dean,
the minimum requirement for a car with u-joints is .120" steel and for couplers it is .063 aluminum. There must be an inspection cover for access to the coupler clamps. We had an incident at Gateway earlier this year with Mark Vaught's car when it appears that the roller bearing in the back of the trans (shorty 'glide) came apart and the subsequent vibration caused the rear coupler clamp to move forward on the shaft. The end result was that the male coupler came out of the female on the pinion shaft at around 8,000 rpm. The shield was the legal .063" deal in a clamshell, top and bottom half design but the impact tore the material below the bolts that held the two halves together at the rear and the coupler made it out of the shield and exited through the cowl just below the windshield. The front bolts held and apart from some distortion the cover was basically intact. If you are running this style of cover I would suggest backing up the bolts with a pair of band clamps around the assembly at each end. The fact that there was only about 3/8" of material below the bolts is what allowed the impact to open the cover up.
The car now has a Rob Moore cover package with adapters at each end for V band clamps holding one piece sleeves that are .120" thick. It is not especially cheap at $600 but it comes ready to install apart from cutting to length to suit the application and it is anodized black. With labor and material costs, plus the clamps and anodizing I could not have duplicated it for the money.
Roo
