[Peter D]

Hilly, I have the same 8-stack as you and originally just used one of the vacuum ports for everything. This did not work well as the power brakes screwed up the ECU's MAP readings. We then stuck the brakes onto the second vacuum port & all was resolved.

With everything daisy-chained off the one port, the "big users" of vacuum tended to affect the "small users". It appears that there is enough volume in the vacuum tank under the manifold to cope with things, providing the big & little users are fed from the separate ports.

I now have things split as follows & it all works well :

Port 1 :

ECU MAP input
Fuel pressure regulator

Port 2 :

Power brakes
Carbon cannister purge valve
Bleed from rocker cover (approx 1/16" orifice)

Kind Regards,

Peter D.