fuel avaporation 401

[mikesay]

Having now returned to the fold after tricky medical period I am tackling a long list of items on my 401 restoration.
One of my earlier problems related to the Solex carbs which I could not get to balance because of much wear etc and as a result I took the plunge and had them rebuilt - wonderful job - heavy on the bank account.
Whilst discussing matters carburration with rebuilders they mentioned that there was an historical problem with heat rise from the inlet manifold leading to fuel evaporation on switching the engine off.
This problem was noticed when using the Solex carbs on Mk 2 Jaguars and was resolved by placing a 3mm neoprene type gasket between the body element of the Solex - the part which faces directly to the inlet manifold - and the next section of the body - it is held by four M5 cheese headed screws. The only problem is that you need some slightly longer screws to cope with the additional thickness of gasket and the longer M5 screws are not readily available since the thread pitch is .75 (point 75) - typical of the French.
Does anyone have experience of this possible mod for the Solex on the Bristol 2 litre.
Regards
Mike Say