fabbing a dual exhaust with stock headers

[old_1966_GMC]

my truck has a 305 with stock headers i want to keep the headers regradless of what i have to do to make this works i want to fab my exhaust to duals ive done the research on trying to keep it with stock headers but no luck so now my luck come to the replys on this thread and all the help from u old & new timers that have done it. PICS are a big plus and other that look forward doing the same thanks. Marco