ENTDOC You can build a Jag rearend for about 600-650 HP and Tork with the right parts and rear support cover for the carrier caps. A 30 spline axle over a 27gives 30% more strength. If you look up the OLD kitcars back in the early 80's there was a test done with anyone who was building cobras. The bottom line is that square tubing is more ridged that round tubing. It also cost more to buy. ERA doesn't use there bodies to provide any structure support of the frame. The test is picking up a cobra in one front corner and lift 2 other wheels off the ground. The round frames on SOME cobras need the body for support. These cars the bodys get cracks to the mounting points. I can't count the number of times I have lifted my car either from the front end or side and to date there are no noises from the car being lifted. You can't say that about other cars. Pick 3 wheels off the ground and see if yours makes noise. Yes I know it's not good for the car. Aluminium differents have been tried over and over again. Going back to the 70-71 Olds Cutlass or Buick 442. The center carrier was aluminium housing was aluminium and they would break very easy. The back lash and side loads would get too loose and blow the rearends. It didn't work then with 375 HP and 500 ft of torque. Today the machine work is better but you still have a HP and torque limit to them. Cast iron is still stronger. If you are looking for the best engineered cobra for suspension, the winner is a BDR with cantalever front suspension setup. You can fine tune this setup better than any other setup, IMO. I have seen just about every cobra in an accident except an originial. At Mid Ohio race track at Run&Gun in 1998 or 1999. Stacy P driving and ERA ran off the track at turn 13 at about 120mph+, damage to the car was both coolers, front nose cone, left quick lift support was heavy damaged. Driver was bruised and walked away with a headache. This was a head on hit. The frame was still straight except for the lift point. I have seen other cars with tweaked frames with less of a hit. ERA cars are heavy and solid. At 2705 lbs with an all aluminium motor and half tank of gas, thats a tank on wheels. I never want to do a head on test with my car, but feel I have a good chance of walking away. As others have said the best built cobra is the one in your garage you built and work on. Your money pocket is a major factor in buying a replica. Aluminium body cobra are beautiful but where do you go to get a dent in the skin repaired? The cost again fiberglass is about 3 to 1. Last point, Aluminium is lighter but steel is still alot stronger for front end parts. Aluminium expands more that steel does. I can always make more power to off set the weight differents.
Rick L