When using a Webber or EFI induction system, it is possible to substitute a long header system with 1‐7/8” primary tubes for the downpipes. These headers have the correct flange openings to mate to the RG cylinder head’s exhaust ports, (which are different than stock Jaguar heads).
A Third option is to substitute a specially engineered tuned header as a substitute for the downpipes. These headers jump over the frame rail to get 6” of straight tube length before any bends. It connects cylinder 1, 5 & 3 to one collector and cylinder 6, 2 & 4 to another collector. The installation of this component requires the replacement of the remoted master cylinder with an RG master cylinder.