Instead of plugging the thing...the cam was changed. That means in all likelyhood the vacum level was altered too. If you remove the hose from the vaccum advance pod's nipple, and then stick a small allen wrench in it..Just small enough to go it the hole..not much smaller, you will feel it engage a screw inside the pod. Clockwise unloads the preload spring, counterclockwise adds preload. If you are surging at cruise, try adding 2 turns counterclockwise. Then reconnect the hose and test drive. I usually tool around and set it while on a drive. It has a reason for being there, and it will add a ton of fuel milage, and really help light throttle driving. Like inclines or hills on the road, etc.
