340 exhaust manifold vs stock 318

REPEAT POST:

"Look at the chart in post #35. It specifically states stock '77 360 log manifold (probably 1 5/8")....that is nothing near the 360 magnum JGC manifold and it's certainly not anything like the ones I used to machine out to larger than the stock 2 1/8"!!!"

What would have been the HP reading with a 340 driver and one of my machined manifolds with both manifolds having a 2 1/4"+ exits?????