I bought mine back in the early 1990's.
The new ones do they have the same amount of mechanical advance built in, i herd they are adjustable.
The reason i am asking my 440 six pack has the timing set at 5deg.I herd i should have at least 12deg i got a vac guage adjusted the timing and its now set at 15deg.Idles way better and more responsive.But now it pings i need to reduce the mechanical advance am i best too weld up the plate or buy the new dissy and be done with it.

on the mopar performance distributor i got it was set at full mechanical advance of 28*, i i remember correctly. i just turned 2 torx screws and changed that to what i wanted.
when looking at distributors make sure you get a quality one. some of the cheaper ones don't have the screws.

Cheaper to weld up to old plate then replace the dizzy. May take you a couple tries to get it dialed in.

I would weld up the slots. It works great.

Someone posted this chart a while back and I saved it. Hopefully, it'll make your job go faster.

Jim



dist. degrees X 2 + initial= total


dist. 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

You would want 36-38 total w vac disconnected so if 15 initial is working good for you with JimG's chart ~.410" would get you very close and you might play with the springs also

I'll bet you need to reduce the vacuum advance rate with a 3/32 allen in through the port on the vacuum canister .

Ive always considered vacuum advance to be very much like enitial. ie: if you're running a lot of enitial (any car with a performance camshaft will generally want that), then back off on the vacuum (if your distributor allows for vacuum adjustments).

If i disconect the vacuume advance and plug it, it still pings.Looks like i will have to modify the plate.Is it easy to get out mine is the early style mopar performance dissy

support the dist solidly in a padded vise, take out the felt,with your longest/thinnest set of needle nose pliers grab one end of the clip,whip it around sideways & up & out & it'll come out slightly bent but havent hurt one yet.

Then it's not the fault of the vacuum advance. Since vacuum advance falls to zero at wide open throttle, or even before wide open throttle it's not usually the problem.

The plate modification will ONLY change the number of degree between initial and total timing. What you may be experiencing is too much timing too soon. With a timing light note what the rpm the timing changes as you rev it higher.

If it's coming in too soon it'll need a stronger advance spring.

The crane springs listed are not available anymore but some of this chart may be beneficial