Check fuel line for trash. Carb to. Check the float level and blow out all orfices like air fuel mixture. What carb is it? If it has sat up that long the fuel will turn to varnish. You might concider a total clean on the entire fuel system. I know it is a big job, but I have worked with and restored old cars after they have set for a long period of time. You can get it to run so-so but you can be constantly dealing with trash in the fuel issues if you don't address it. I used to live in a very humid area and sludge in fuel tank was always a problem....real nightmare. Next check timing and coil voltage and resitance. As long as it will stay runnig with adjustments then those areas would be a good start. If points had problems than it would not want to fire up unless it has electronic ignition. I hope this helps. It won't be a big fix but it may involve a few steps. I'm sure there are a few older guys out there that have some good ideas. Post your progress. 70 is a great looking body. Good luck and have fun with it.