I just started my 66 396/360 engine Saturday for the first time it was rebuilt about 2 years ago. I let it run for about 20 minutes and I still had a little bit of blue exhaust smoke should this clear up or should I be worried? :confused:

:hurray:I'd say,put some miles on it.
Put a load on it.......meaning drive it hard uphill,not a bunch of lumber...;)
this will help seat the rings.

Yup,just as Dan stated for sure.

after the cam breakin oil is changed run that oil approx 300-500 mils and dump it too with filter.

Then refill with fresh oil & filter and take her out and get into it pretty hard throught the gears a few times like a couple of hard 1/4 mile runs would be. dooing this will help seat the rings,i had to do it to mine to get the stubborn plasma moly rings to seat .

scott