[Healeys] Vacuum take-off on Weber manifolds.

[John Rowe]

Simon
My thoughts!

Block off two of the balance tube holes in the manifold- use the third for
the brake booster vacuum. With these all connected you will find it hard to
tune the carbs-remember there is a mixture screw for each cylinder to do
this. This system has worked well for most people who run Webers so why try
to change it

I would forget about the idea of vacuum advance with this setup- there is
possibly no benefits-at least there wasn't for me. I run an Australian
designed modified Bosch with no vacuum advance mechanism very
successfully-as Kees said run about 10-12deg initial advance with IIRC 34deg
total.

Spitting back through carbs is a symptom of lean mixture but this should be
confirmed and rectified when put on rolling road. Mine required richer idle
jets.

I assume your car is RHD and the manifolds are Webcom design. These  should
fit without any modifications apart from the front support to the shroud
maybe. I had a set of these but donated them to local Healey fundraiser for
auction and bought a set of DW which required some mods also.
Cheers
John Rowe
Qld Australia