[Jermike]

I just changed the valve cover gaskets on my Mustang and ran it
for about 5 minutes and there is smoke coming from the engine compartment. Is this normal?

[fastbck65]

It is normal for gaskets to smoke a little when first installed. If you haven't done anything else to it that should be the only issue causing the smoke.

[astumpf]

its a very normal occurence. when you popped the valve cover off, a little bit of oil probably dripped onto your exhaust. after the exhaust warms up it will begin to smoke and continue to do so until the oil burns off.

[Mustang Nazi]

You got a leak, Pop the hood and look.