I am installing new dual 40's in my 914-4 and have some 1/4" manifold spacers from an old set that I replaced a while back with a single 32/36 in my time of need. Now I am not sure why they are used and whether they need a gasket also (or 2, one on each side?)
I am looking forward to your feedback, but please remember this is not a question of whether or not to use the duals, but a help request for the order in which the spacer should be installed in the stack.

Thanks in advance,
Steve

The only spacer to use is a phenolic spacer which is pre-made with a gasket on both sides between the head and the manifold.

FWIW: It was recommended to me not to use the manifold to head spacer as seen on the stock fuel injection as the fuel is not injected right the head/manifold opening like the stock config and the heat is needed in the manifold for atomization and keep fuel from pooling. Spacers at the base of the carbs will keep the fuel from boiling out of the bowls.

Thanks for the support and feedback for both sides of the decision. It turns out that my studs are not long enough to to accept both the spacer and manifold with room left over for the nut so I guess my decision is already made for me.

Steve