Howdy All:
Dave- Supply and demand!
Dripblade:
There sure is, but, the question is "How much can you spend" and "How far do you want to go with it?"
To be more specific than what I'm about to suggest I'd like to hear your plan, an estimate budget and a general goal. Is this car a daily driver that you have to rely on? What is it's condition? Is it an automatic trans?
In the meantime, consider-
*Increasing the initial advance by 5 degrees over stock.
*A fresh tune-up is always a good idea. YOu will have an electronic iginition system which is very reliable and strong. But it still needs periodic service to the cap and rotor, and the plugs need to be replaced as needed.
*Make sure your air intake system is hook up and functioning properly. make sure you air cleaner element is fresh and clean.
*dejunk and unclutter the interior. Don't carry anything you don't really need for safety, emergency or comfort. Less weight means more performance and mileage.
*Make sure your tires are aired up to the max PSI rating printed on the tires.
*Consider synthetic oils in the engine, trans and differential at the next change.
*Make sure your exhaust system is clear and functioning properly.
While none of these suggestions are rocket science, together they could add up to as much as a 10% increase in power and economy, depending on your current state of tune.
Know that a '77 250 is somewhat encumbers with EPA restrictions that limit performance. You should know your area laws and requirements about such things before you start major modifications.
There is a bunch of info on this forum. I'd suggest that you get real familiar with what's here, let us know more about you, your car and your goals.
This should get you started.
Adios, David