That flex head gear wrench seems like an excellent ideal and fast as well.. Good thinking. On all previous occasions I have removed the manifolds unfortunatly to get at those back carborator base nuts. Just loosening the manifolds was never an option for me as I would not expect to get a good reseal when retorquing them. I do not win lottos either unfortunatly. I have also dealt with very small intake air leaks causing one cylinder to drop out or run very poorly a few times with undisturbed manifolds. Also that fitting for vaccum near the rear of the intake manifold has caused trouble once or twice for me. Spraying wd 40 finds the little darlings most of the time. But again my experience is very limited.