Spray some carb cleaner around the base of the car & such, keeping it away from the intake barrel.. If rpm rises u have a leak somewhere..... vacuum or gasket
Also check carb bolts to manifoeld for tightness
I pulled manifolds off 3 times . I got the good gasket Everyone said to get . It's got all them tight to the higher end of the spec . Using carb cleaner I see no signs of leaks at manifold side
