bb shorty headers??

[yodaman43l]

I need to find shorty headers to fit a '70 BB 2wheel. I plan on running the exhaust through the frame instead of below it. The header manufacturers claim "no application available" but there is so much room. Anyone done this mod or know of an application that would work? I have seen later model BB p/up headers or possibly same generation camaro's or chevelle's???

Thanks