Oil in coolant, engine sputtering

MVRCorp said
Best trick I know to check for vacuum leaks is a can of WD-40. With the engine running spray the WD-40 on the gasket between the intake manifold and heads and also between the intake and carb. If there is a leak you WILL hear a RPM difference when you hit the leaky spot.

or you can use a propane torch just dont light it the engine will idle up once it sucks some propane in i have used both tricks here and both work great propane is just a little less mess if you have one at your disposal