I don't know about the LCF, but the "normal" truck used a crossover under the front from the factory. It was not flexpipe, but it was routed that way.
If yours was the same from the factory, you probably need a new set of exhaust manifolds to do it "right". Any of the SBC ramhorns should fit, then you can get your favorite brand of pipes to connect to them and route as desired.
Note: I am assuming you have a V8. If not, ignore everything I said and let us know what engine you do have.
