@tomkuester posted:Some good information was provided here.
I'm no longer interested in pulling the motor for a proper dino test, those days are behind me, but I like the car to run as good as it can with my Weber setup and a new mechanical advance only Mallory dizzy. I like the Mallory unit because it's small and easily fits under the screen. It also comes with a number of springs, providing six different advance curves. the lightest springs show all in at 2400 rpm. The stiffest springs are all in at 5500 rpm. Then there is a matter of the advance stop bushing allowing a good range of rpm options. I'm playing with the options, but access to the dizzy is a pain.
You should be able to find a shop with an old SUN distributor machine. They put the distributor on it and can set it to your specs.
For the street you want the total advance in for where you would be cruising. That is probably around 3,000 to 3,200. Often the rate of advance is arrived at by using a combination of springs like one heavy and one light which theoretically puts it in the middle somewhere.
I have a Ford Motorcraft distributor in mine with the small cap and it fits perfectly fine. The limiting factor is actually in this case the intake manifold which only considered fitting the small cap. The large cap will not fit between the carbs/runners.
There isn't anything wrong with the Mallory but it is a little bit different of an animal.
You can try the lightest springs and see how the engine runs with them. I think it will ping bad and secondly, the thin light springs tend to wear out rapidly and stretch to the point of not returning to zero. Ask me how I know?
The aftermarket distributor springs are not good quality. The Ford's you can't kill. I had a Mallory and an Accell. I couldn't keep advance springs in them. That's why they got replaced. No other reason.
Fortunately or unfortunately, Ford distributors and ignitions are the most reliable.