Magnum swap down pipe info

65 Dart magnum 5.2, 4spd , 72 dart ex. Manifolds.
Trying to find dual down pipes to begin fab.
Had flex pipes previous to get car drivable.
Now retro fitting 64 powersteering box/pump.locating pump under battery tray.
Anyone know somewhere to get something for starting point without spending $600
On something gonna have to cut....?
Preferably 2" to start.

Also need a 94" 7 rib belt that is unheard of
To make work. Could re rout belt but defeating tensioner.....

Or do I get different PS pump and start over..lol

Thanks. In advance
Dave