I have a 71 Challenger with a small block, and I have TTI headers on it. They fit good, and weren't hard to install from underneath. They have step tubes that start out as 1 5/8 and then go a foot or so and step up to 1 3/4. I don't think I have enough motor for headers like that, but they fit and work good. Another option is Dougs headers. Dougs headers have tubes that are 1 5/8 all the way to the collector, which would be better for a stock type motor. Like the TTI's that I have, there are no tubes hanging below the drag link....and that is what keeps them tucked up under the car where they should be. Neither brand is cheap, but you get what you pay for.