i think i found the problem to my very low FE

the timing chain is very loose, posibly even with a lot of retarded timing, retarded timing on the valve guives low FE a no torque

i have a air gap where the manifold meets the engine, old seals i guess, wich is guiving me a lean mix, when i adjust the carb to be ok at idle i get almost ok mix at idle and rich mix above idle....

solution

fit timing chanin kit and adjust valve timing to the correct advance

remove manifold and fit new seals

will take the time to pop the head and fit a new gasket and to clean out everything

will post in a month

Sort of makes sense; a really slack timing chain and hooked sprockets (The teeth wear from being symmetrical into a sort of shallow hook shape, hence the name) could put your cam timing out. If the car takes its ignition timing off the camshaft, that will then be out too.