my 350 smokes after engine temp reaches about 185. 7 out of 8 spark plugs have oil on them. i am running 10w-40 valvoline in it right now. heres my question... since my engine only smokes after the car warms up, if i switch to a straight 30 or 40 weight motor oil, could that solve the problem? thanks for the help.

Probably not. The viscosity will be the same at temperature. Just run a leakdown test and find the problem. Heavy oil won't fix bad rings. (Bad valve seals typically cause smoke at cold start not when engine gets hot)