[Fishcop]

Steve, as CamB mentioned I recently replaced my Marelli for a Bosch.

On the excellent advice of the esteemed John Walker (John Walker Workshop) I obtained a relatively cheap 1974 bosch dizzy. It needed a freshen up, so I rebuilt it courtesy of one of Warren's (Early S Man) instructional posts. The advance in a 2.7 S dizzy (other than the Carrera) is the same as the earlier T engine. I also purchased a new rotor cap and rotor button (rev limited to 6500).

Whilst the body of the distributor was dismantled and free of obstructions, I took it to a local performance engine rebuilder and had the shaft machined to exactly match the shaft of the Marelli. There is a width difference of about 2 mm and the O ring is in a slightly different spot but this does not matter (but you must get a new O ring to match or use the old Marelli one).

I then rebuilt the distributor and added a Crane XR 700 optical ignition unit and new leads. The overall improvement was incredible. Your hardest task is to track down a suitable dizzy, but trust me....you will not find an original second hand Bosch to fit!

Good Luck