BB's of grease???
 

I have noticed upon starting my engine to start my day, I have little balls, about the size of BB's come from my stacks and land on the hood of my truck.

They do not stick to the hood, but blow away with the wind. I got one up and squeezed it between my fingers and it was like grease???

Any ideas what this might be.

I have a 1985 FLC Day Cab, 350 BCC engine.

Rain may have gotten in the stacks. When you fire it up it snows black stuff all over. You ever see guys with bologna cut stacks put buckets on their pipes? It's to keep the water out. It's good to do if the truck may sit for a while.

Yeahbut that stuff sticks to everything, and his didn't. I'm thinking soot balls? Carbon is slippery, and I can imagine a little ball of soot might feel somewhat like grease. Not sure, but if it's coming out of the stack, and it's black, and it's an '85-vintage truck, it's probably to be expected.

Thats just soot if the truck is dry it'll just blow off with the wind. If the truck is damp or wet it'll leave a black mark that'll rinse off with water. No big deal. A lot of older trucks do it. New trucks with Cummins seem to have a lot of wet soot which can make a mess on the truck.

agree with the rest especially if you have straight pipes.
one thing you might want to do is to screw on a metal flap to the top of your stack(If they are straight pipes) so when your engine is shut off the flap will cover the opening