Triumph Repair: GT6 Axle replacement or upgrade, modified street cars, datsun 240z

Question
Hi, would like to know options of replacing rear axle's. I heard that they used Datsun 240z and Opel GT axle's. Please can you provide more info coz it has to be modified to fit. I'm fitting a Rover V8 3.5 into my GT6 MK1

Answer
Hi Marnitz,
I have seen different rear axles put in many of the British cars but I never heard of any that were bolt in without modifications. I am not a fan of an IRS in small modified street cars. But that is just me. My background was motorcycle flat track, so I loved going sideways. When I went into working on cars I brought my love of "sideways" with me and just playing with many of the IRS cars, I found the IRS great for maintaining traction over rough surfaces but going sideways is not about maintaining traction other then trying to control it. I found most stock IRS cars were unmanageable when sideways. The Jaguar was the only one that I was comfortable with, but I believe that is too large and heavy for a GT-6. I don't like the geometry of the "Z" cars IRS as I repeatedly "lost it" when full lock sideways. A friend was one of the top SCCA drivers in a "Z" car a few years ago and he modified his and said he had several times went sideways (not good in a race) and was able to retrieve it.
In my opinion a straight axle makes more sense for a small street rod. (as much as 5 HP is lost by each "U" joint, not counting the extra weight of a IRS)
I am presently "stuffing" a 3.5 (215) in my MGB-GT so I know How many hoops you had to jump through to get that "Wide" V-8 into a small car. So finding a small IRS that can handle the extra load that a V-8 can produce is going to be a factor for you. A Jag could handle the load but is heavy and would have to be cut down as it is too wide. A "Z" car may handle the load better than the GT-6 but I think it too is too wide and it's goofy geometry turns me off as a candidate. I do agree that you need to get rid of the dangerous and poor design of the GT-6 "Swing Axle" as VW and the early Corvair found out the hard way. But, I guess it depends on what you are going to use the car for. keep me posted as I am a fan of "Chop, Cut and Modify"
Howard