300 straight 6
2 Answers
I would look for vacuum leaks and try adjusting the idle. Your carburetor may be due for a rebuild.
It sounds like a vac. Leak to me. Try to find a leak in the hoses first look for dry rotted hoses and if that don't work... with a cold engine start it up and spray some starting fluid son the carb gasket and see if the idle changes if so it's prob. A bad gasket.