So I have just got my 39 running. I am using a stock GM points Distributor in the 283 small block. New Points NOS Mallory condenser from the 70's so its good quality. Timing is at 12 degrees advanced. Here is the issue. I can go out and crank it up to start and it will fire right off and idle perfect, Shut it off, and you might be cranking it for 20 min before it will fire again, sometimes poping out the carb, sometimes poping out the exhaust. Turn it off, then back on hit the button and it will fire right up. make no sense at all. I pulled the distributor and set it all back up again, put it back in and it fired right up. Having only about 1 mile of drive time on it, I took it for spin around the neighborhood. It was running but not as smooth as it should have been, and somewhat lacking in power. it was then that I noticed the Tach was acting very weird. I could rev it up, but it would never go over about 2500 RPM, and was very slow moving. So I have a Feeling this tach is not working properly. It just didn't seem to line up to what the engine was doing. Got back to the house, pulled in the drive way, shut it off, went to fire it up, and same thing......no start, pop out the carb. shut it off came back 10 min later fired right up. Now my question is this... The tach is a neat old AC Delco Tach, that is def old, was NOS in the box when I got it, It was marked for an 8 CYL on the rear case, and required no box to drive it. its just hooked straight up to the coil negative terminal. Is there a possibility, that this tach, is causing me issues? can it ground out the negative side of the coil and make it do weird stuff in the process? I plan on disconnecting the signal wire from the coil this evening and test it. Im at work now and just sorting of thinking out loud about it. Any thoughts, experience or input appreciated.