David
There is a complete solution to the clamp problem, it solves many issues and gives more power.
The system costs £440 complete all in stainless steel, 47 mm bore pipe and free flow silencer with the 3 branch manifold. It is a copy of the Vic Derrington mods on my car, I did the anti roll bar for the front suspension.
I get the system made to order takes 3-4 weeks.
My car also has the Alexander Overdrive gearbox
Trevor