just guessing here but i would think you need long tube headers, then at least 4 90* bends.
So headers down, then maybe extension to get under firewall, two 90* bends ( one right one left ) maybe some short tubing to run to the outside of car, another 90* bend to run into the side pipes..
there are a lot of on line store that sale the chambered sticks for vette's shouldnt be hard to do,
My next mod is the chambered exhaust under the car and out the back, but i need to try to fit 3"