Why would you plug the vent tube? Where do you expect the water to go when it heats up and expands? Where do you think it will go? It has 2 places to go, out the cap or thru the head gasket into the combution chamber. Your solution make no sense to me. The vent tube is there for a reason. If your arm was broken would you have the doctor cut it off? You haven't solved the problem you have eliminated the symptoms. You may be satisfied with your solution but it will manifest itself into other problems down the road.

I may be wrong but I believe that for every pound of preasure that you add to a system it increases the temp by 3 degree. So your 7 lbs cap will raise that 195 to 216. So I would recomend 2 things go with the 0lbs cap and put in a 180 or lower thermastat.

Sorry to rain on your parade. All I can say is enjoy your truck while it is running fine.

Brian Moore
1949 3100 5 window Deluxe
"Today is better than yesterday, but not as good as tomorrow"