Exhaust kits?

[myyamr7]

In a month or so, I'll be swapping the SB 350 in my truck for a BB 402. The engine will be rebuilt and will require the 20-30 minute break-in on initial start up and I'd rather not run it like that with open manifolds. I have some exhaust shops close by to have a system made, but it'll be a pain to try and get that done with the engine not running.
Looking around, I don't see much online for full kits for the big block, most are header/cross member back kits.
Does anyone know where I could buy a quality pre-bent system, just bolt it on and go?
I would try and cut/fit/bend the small block system just to get me to the exhaust shop, but I know that won't work seeing the donut gasket for the small block actually fits inside the big block manifold.

Thanks