340 HP's vs headers

Got a set of hedman block huggers coming. I will make my own downpipes. Off thesr while on my 318 mockup motor.

The 318 runs great, and is stock, i will prob do what others have mentioned, and put a good timing chain on it, install those 340 exhaust manifolds on it, get an LD4B and an eddy 600 and drop it in my kids car. For now it will still be doing mockup duty for the downpipes for this car.

Anybody know where i can get 2&1/2" diameter muffler tube mandrel bends that i can cut apart and make my own down pipes out of. I'm thinking i can do this, and buy the header type exhaust kit from summit, and add another set of collector flanges to tie it together.