Fluid on exhaust causing smoke - 69 with 396 and auto.

[Slowboat]

Hi Everyone,

First post here. I have a recently purchased '69 C20 with a 396 and T400 auto trans. Earlier today I noticed a bunch of smoke coming out the back, especially when I went up a steepish hill. It isn't coming out of the exhaust, but either oil or ATF is dripping onto the exhaust (doug's Tri-Y headers) - it seems like it is hitting the passenger side header.

I got it home and noticed that the dipstick was out of the auto trans filler tube about 1". Would ATF come out of this - especially if you are going up a hill? The valve cover gaskets are leaking slightly (another project), would these get worse going up hill?

Anything else I should be looking for? I don't want to drive it too far until I get this sorted out.

Thanks,

Noah