Setting point and dwell

Absolutely not. The only way that would work is if you have a distributor tester. I actually do have one, but you have one major advantage in that your distributor cap has a sliding metal door on the side so you can set dwell while the engine is running. The rest of us have to pop the cap off, adjust the points, put the cap back on, then run the engine to see what we got for dwell. Often that has to be done over and over until we decide it's close enough, and give up.

The other problem is dwell is much more accurate than measuring point gap. For example, you might measure your point gap to be.018", then find dwell to be 22 degrees. After adjusting dwell to 25 degrees with the engine running, you might still find the gap to be.018".

If access to the door is a problem, look at the orientation of the vacuum advance unit. If that will not end up tight against the firewall, consider removing the distributor, turning the shaft one or two teeth, then reinstalling it that way with the body turned the same amount. If you have the clearance, you can also rotate just the body without removing the distributor. This is where a lot of us run into trouble for some reason. The idea is to rotate the distributor one direction one eighth of a turn, then pull the spark plug wires and move each of them back one spot the other direction so they end up in the same place they were. When doing it this way, the rotor hasn't turned, so you want the same spark plug wire to be right over it when you're done. Often we end up with a major misfire because we get two or more wires in the wrong spot.

If you do move the distributor one eighth of a turn, then find the vacuum advance mechanism is too close to the firewall, you can still do this to adjust dwell, then rotate the cap and plug wires back to where they were. Keep in mind too the engine rocks left and right, and you don't want anything mounted on the firewall that could be hit by the advance unit. Also, if an engine or transmission mount breaks, the back of the engine could lift up, and the cap could hit something. The more common problem is often the engine has to be raised up when removing the oil pan to replace it or the gasket. Once we break a distributor cap from it hitting the firewall, we usually remember to check for that the next time, but it's far smarter to orient the distributor so that won't happen.

Even if you don't want to pursue these ideas, or you just can't get through the door with the hex key, consider removing the cap, then adjusting the points with the distributor still in the engine. That eliminates a lot of things that can go wrong with the reinstallation. If there is room to pull the distributor out, there will be plenty of room to get to the adjustment screw.