Didn't see this thread earlier.
My headers are from a late '70s 4X4 truck and I'll bet they're a Blackjack or equivalent cheapie brand. They look very much like the Hookers above but I believe they have smaller tubes. I removed them when the new owner purchased the truck from our dealership (he wanted manifolds) and they dropped into my vehicle without any hassle. The only change was to re-index the clip which holds the clutch return spring at the steering box. I have a factory V8 truck.
These headers were installed around '96 and have never needed gaskets. Making headers seal in low power applications isn't usually a challenge. First, put a flex joint at the collector. The engine wants to rotate and flex in it's rubber mounts so don't expect the attached exhaust system to stay together when rigidly attached to the engine. Most of the time I simply find a steel or ceramic exhaust donut that fits the pipe and that does the trick. Second, with cheapie headers I ensure the head mating flange is flat (welding and machining with a Bridgeport may be necessary) then I cut the flange into three sections for front , center, and rear tubes to allow thermal expansion and contraction without warping the flange or forcing the gaskets out of shape. This can turn out to be a fair amount of work though and I wouldn't recommend paying a machine shop to do it.
85-91 Corvette exhaust manifolds are similar to the Ram's Horn or Tru Ram and can often be found for short money at swap meets or online. It flows better than a cast ram's horn.
http://www.ebay.com/itm/CORVETTE-MAC...539803&vxp=mtr
92-96 LT1 Corvette manifolds are more durable and flow better but are more of an exhaust manifold than a header.
http://www.ebay.com/itm/92-96-C4-COR...8431f1&vxp=mtr
Original ram's horn manifolds fit perfectly and there are no clearance issues. I would expect the same from the manifolds above. Cannot say on the Tru Ram as I've never had a set in my hands.
Long tube headers will do more for low end and mid range performance than short tube varieties. Installing a crossover tube in duals can reduce exhaust noise and increase flow some. I removed rams horn manifolds to install my headers and I'm still happy with the decision.