[Excaliber]

One of the main advantages of a replica is it's relative light weight compared to other cars. Because of this single factor the read end components are NOT subject to the typical stress factors you would see on a standard issue "car". Traction loss usually comes WELL before any serious stress loads are seen.

Now if you want to go dracing with sticky slicks and ultra low rear gearing there is no question which is strongest, Ford 9", end of story! But the 289 and 427 cars, drag or road race, ran well with the original style (Jaguar like in specs) rear suspension. The full blown "drag race" only Cobras had the rear gears heat treated for additional strength and they DID want to run a solid axle (like Ford 9") but Shelby would not allow it. Bear in mind these cars ran gearing like 5:13 to 1 rear ratio and massive slicks!

ERA's approach to strengthening of the half shafts makes them pretty darn bullet proof! I have heard of CV joint failures on other IRS systems, but I would not conclude that is because of excess stress levels (high horse power). It seems to be more about "quality" control and defective parts or installation rather than "broken" parts.