Hi Pete,
Glad you were able to improve the shifter feel. We have extensive experience with rod shifters for ZF applications for center and right hand drive - right hand shift applications however have not yet been involved with cable shifters as per Getrag applications.
Regarding future upgrades, we've already got the back end of the car covered. There's no need to re-invent that wheel, as the saying goes.
Please check out our posting under parts for sales - new prices. We offer a complete four corner kit for track cars or serious road use. The bolt on kit uncludes four new fabricated steel uprights with improved geomerty built in, brake cooling built in and vastly stronger without weight penalty.
The kit also includes new reversed lower A-Arms that provide toe-in adjustment via rod end, support the upright and trailing arm clevis pin in .750 precision ball bearings, thus eliminating all bind inherent to the rubber bushings. We've also built into this kit reduced rate of camber climb on the rear, raised the instantaneous roll center height to increase roll resistance and provided more anit-squat.
These parts took hundreds of hours to design, prototype, test, revise, tool up and put into production. The results work, with many cars already running on all four uprights and some with one end done first, in every case you can feel the difference right away in the controls, the car becomes more responsive and easier to feel at the same time.
In your case, it sounds like you want to put some track time on this car, you really need to check out these parts, please give me a call on the toll free number. We can save you a ton of work unleashing the potential in the CAV GT monocoque chassis. Thanks
Cheers
PS: the pic below shows the original CAV cast upright left, new steel upright center and the original Ford GT40 upright cast in magnesium on the right. We have gone as far as possible to the configuration of the Ford part within the limits of chassis pick up points for the suspension and maintaining an easy retrofit installation.