c;

Your post is a bit fragmented but it sounds like a typical after winter storage situation...you first need to determine if the battery is still good and capable of holding a charge...charge the battery (overnight with a plugged in 10A or so charger), then perform a load test...an auto electrical shop can do this for you inexpensively. A 6 year battery can still fail way before that, especially if you let it discharge totally in a stored vehicle...lead acid batteries want to be fully charged...all the time! That bat may indeed be shot!

You should monitor the system voltage while driving...above 2000rpm it should be >13V... if not, charging system is suspect.

If unmodified, a '67 122 has a 30A (on a good day) generator, which is adequite for the car but only if all connections are clean and if all components are working right....which is likely not the case after close to fifty years. Alt conversions are certainly possible, and by upgrading the ch sys output to 60A most people are very satisfied...it brings the electrical system from marginal to having lots of headroom and makes a world of difference in the confidence department....but before you think about installing an alt, you need to charge and have the bat checked!

See also: http://www.sw-em.com/gastight.htm
and http://www.sw-em.com/altkit.htm

Cheers