timing advance (to much)

Here's a chart someone came up with, approximate slot length VS degrees advance

NOTICE that these figures are DISTRIBUTOR degrees, multiply X2 to get CRANK degrees

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