65C10,
I don't know what part of Denver you're in, but I've had pretty decent luck with Exhaust Pro's in Northglenn, and Commerce City.
Or if you're remotely close to Brighton, I know an old time radiator/exhaust guy that does real good work for real reasonable prices.
He split the manifold and put duals w/glasspacks on my 46 for just over $250.
