Hey Ant, I think this is supposed to be
Track - (2 X .5875) = 56 - 1.175 = 54.825" flange to flange.
Rick the track should be centre of the tire to centre of the tire. The outer suspension pivot points should line up with the tire centre or you will get scrub steer. This is important as you know how heavy your steering gets with a worn balljoint never mind a mislocated one! This is where it gets confusing as Robert points out about every piece of cobra literature I have seen with specs gives a 56" track front and rear for the 427 and coil sprung 289's. The chassis instruction/ owners handbook for the 427 gives a track of 53.96" on the front for std and racing and rear is 53 std and 55 1/8" racing. These last couple of numbers are I believe the flange to flange dimensions not the track dimensions as that is what works with the dimensions I have compiled for the rear. That allows for different wheel widths and offset between the different models ( same track though ). The 52.5 and 51.5 numbers are for the 289 and coupe which was built on the roadster chassis. Chopper it was the "289" roadster with 3" frame rails and leaf sprung. I believe the Kirkham hybrid reference is the 289 body on the 427 (4" frame rails ) coil sprung chassis.
Ant, what parts are you working with? Are you stuck with frame mounting points or the stub axle mounts as you need to establish some points for dimensions considering bumpsteer, steering rack length, tie rod lengths, roll center height and on it goes. If you are making the a-arms you must be able to move some points to get your geometry correct.
Grumpy, could you send me the info you sent Ant also please. Remember your buddy who sold you the FFR interior at a good discount
