Vacuum Advance Connection HIF 4 | MG MGB Technical | MG-Cars.info
Quite a debate on the merits of manifold or carb vacuum porting to the distributor advance.
The only difference on the vacuum is at tick over speed – beyond tickover the vacuum is the same whether at the manifold or the carb.
I personally prefer the carb porting as i reckon i get a better slower tickover.
Read the debate from the link below:-
http://www.mg-cars.info/mgb-technical-bbs/vacuum-advance-connection-hif-4-2014031909192510757.htm