Small block and big block exhaust interchange

[Slooptin]

Might be a stupid question, but will a stock exhaust system (post manifold) from a small block truck bolt up to a big block and vice versa? I have long tubes and true duals on my big block and I want to go back to manifolds and a 2-1 and wondering if I can just slap in the stock exhaust from a small block truck and extend or shorten the mid section as needed?

 

[SquareRoot]

Manifold width will be different, otherwise no issue.