After doing a engine swap and putting 520 miles on it, i had a large amount of smoke coming from under the hood and sometimes out the exhaust. I assumed the intake gasket had not sealed properly and started to tear down the intake. during this process i found that the valve cover bolts were very loose, and that i had oil in my plenum. Lost a spark plug to fire in the driving process. i also have smoke come from the heater vents on occasion and the heater is always on. I have low vacuum causing the brakes to be difficult to engage. Just wanted to get your thought before i continue today.