[Jac Mac]

If you mount the rear upright in its correct position it wont look as bad as your top link & upright is well forward of its correct position in the first photo above. You really need to mockup your rear suspension as accurately as possible in order to measure angles etc and compare them to the limits of the CV's operating range.
Having said that if you can get the motor further forward even 30/40mm by notching the chassis/ cutting down a pulley size/ or removeing a non critical lug or engine part it would help a lot.
With that motor in place its easy to see why the GT was a bigger car than the GT40