vivivivivibration

did the break-in on my 340 a couple days ago.things went fairly well.had a couple of friends over to help me out.one started the car and kept it around 2k while I set the timing to 34*.It smoked something terrible out the left bank.don't know if it was oil in the exhaust system, or the rings in number 7 cyl. that I had to wet sand do to some rust from being stored for years.anyway the smoke was so thick you could,nt see the end of my 60' shop.anyway about 14 minetes in it finally cleared up.A friend that was familiar with this car,when it had the old 340 in it,said it always hade a vibration in it.well I still do.I used the same balancer,flywheel,pp,and clutch disc.I need to find what it is.I thought I read something on here about the 340 had a special balancer on it,not the same as a 318 or 360,is this correct? or not?thought I'd barrow a balancer and see if that fixed it ,before buying one.whats your thoughts?:poke: