Smoke from exhaust, carb, engine, pipes

[crowdaddy]

My 230 inline six is smoking today. (in a bad way). 64 c-10 has a manifold leak,and exhaust leak. I've been making arrangements to take it to my mechanic, (paperwork, title, ect.), also, running it daily around a trail. It didn't start smoking bad until today. Other days it smoked with the burning off of the old gunk in tank and seafoam and carb cleaners. But this is excessive.

I recently filled the gas tank after draining some of the varnish and gunk, figuring it would have a cleaner mix to burn. I think I remember putting a can of seafoam in the tank also that stuff called heat, and a small amount of injector or port cleaner.

It somtimes looks whiteish, and somtimes blueish. Not sure I want to take it to my mechanic, unless I must, with a trail of smoke through town. I suppose I could drive it there at night. Anyone have ideas about whats gone wrong. It has been sitting in a barn for 12 years.