1973 340 issues.

Rislone will help free up sticking rings and would help IF that is the problem. You just have to try. And more miles may help... again, you just have to try. But, the smoking under hard acceleration is a classic sign of bore and ring wear, so don't get your hopes up too high.

Use about 1/2 to 1 teaspoon of oil per cylinder... just enough to work around and coat the rings.

And just for historical grins... 30-50 years ago, JC Whitney sold pills that you would put into the cylinders and they would bring up the compression for about 100 miles.... maybe 200 miles in an older low CR engine LOL