Here is a Post with a Chart on the First Reply:

There's a "backyard chart" of slot length to degrees advance............

Dimensions for Mopar distributor slots, in DISTRIBUTOR degrees

Modifying advance slots
degrees / slot size
6.............. .340
7................355
8................375
9................390
10...............405
11.5 ...........420
12...............435
13...............445
14...............460
15...............475
16...............490
17...............505
18...............520

http://www.forabodiesonly.com/mopar/archive/index.php/t-182247.html