Msd

Lock the advance and set your box to use the "start retard". That will retard the timing 20 degrees until you reach 800 RPM then restore full timing. The retard will kick back in when you drop below 500 RPM. Here's what the instruction manual has to say:

Cylinder Select Cyl.Select w/ 20° Start Retard
0 = 4 cyl. 4 = 4 cyl.
1 = 6 cyl. 5 = 6 cyl.
2 = 8 cyl. 6 = 8 cyl.
3 = 6 odd 7 = 6 odd fire

START RETARD
[FONT=Swis721 BT,Swis721 BT][FONT=Swis721 BT,Swis721 BT]The Start Retard will be activated during cranking only when the Cylinder Select dial is in the 4, 5, 6 or 7 position (Figure 2). During cranking the timing will retard 20° until 800 rpm when it returns to the mechanical setting. If engine speed drops below 500 rpm, the start retard is activated again.

As far as the best way to lock out the advance, based on my assumption that the mechanism is similar to that in a Chevy distributor, I weld my shaft then grind the weld flat. Sorry for the Chevy comparison, but I'm completely new to Mopars and am not too familiar with them....yet. :snakeman:
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