school me on dist

And this by DusterIdiot. Again I appreciate everyones efforts to help me ( a not so bright guy ) get a handle on all of this.

You can install the longer slot, but if you set it to have more initial you could cause the engine to ping/ or detonate at a certain point because it lit the mix in the cylinder too soon. On a low compression engine, like ours giving the combustion process a "leg up" by limiting the governor and setting the base timing starts the process sooner so the cylinder builds pressure sooner...

As noted we are lucky to have a particular formula to work with on timing
(base+mechanical=30, and with vacc. advance at cruise =50...for a truck I advise to limit to 30 and 47 due to the power to weight ratio and lack of aerodynamics).

So if you follow to articles...the truck distributor would be set at:
4 BTDC base+ 26 springs and governor at just above highway cruise rpm=30 then your vacuum advance on top of it....

The super six distributor gets to light to fire off earlier:
12 BTDC + 18 BTDC springs and governor=30 then add the vacc advance.

That extra 8 degrees helps for a more complete burn of the mix compared to the 4 on the truck.

There are only a certain set of governors mopar tended to work with, and an end user like your self can break out a welder and file/grinder and make whatever version you want:

slant six 9 (super six),10( mopar performance distributor),11 (stock 1976 applications,13 (truck distributors),15 (1973-1975 cars) and points 11.5 (early to mid-60's distributors),13(late 60s to 1972 distributors)
V-8 17,18 (too much for a slant six but worked fine for those 4"+ bores)
Points could be had in anything from 9-18 (but you can't use an 8 point governor in a 6 cylinder car)

Remember emissions timing is to provide a controllable amount of pollution per the regulations and specs when everything is working correctly. This does not necessarily help with power and economy, adding a little more base timing will help get a few more HP out of a
low compression engine but may create a little more NOx (thus the need for a little more EGR in the 1976+ vehicles along with the catalytic convertor...so the combination evens the gains and losses out).

Typically when someone wants a shorter slot that 9, it desired because of the limit in timing with boosted engines, or because the performance build needs less timing due to the fuel or combination being run to stay out of detonation.