mopar dizzy help

[Shields14]

i bought a 69 coronet that somebody else put the mp dizzy in with orange box.. what i am wondering is what does the ballast resistor do and what should my electrical readings read at the coil at the battery at the resistor. its a 72 440 been rebuilt  valve job ect ect nothing to wild  at least thats what i was told  it has a different cam in it also. not sure of the specs but it sounds pretty good. problem i am having with the car is real doggie off the line and kinda cuts out and surges a bit then after acout 2500 rpms it levels out and runs descent..  new 670 holley street avenger  71s up front 75s in the back with yelow spring.  initial timing is at 12  and total is 40.  maybe 40 is to high if so what is the best option to bring it back down to 36ish.  feels like ignition problems to me but just dont know alot about this stuff  any help would be greatly appreciated.

[BrianShaughnessy]

Total ( w/o vacuum advance ) should be around 35 degrees...    and initial could probably be a few degrees more...  16ish...   maybe even 18 depending on the cam.

If it's a stock style dizzy then welding up half the advance plate slot  usually gets you in the ballpark.   And a file gets you the rest of the way.

[Shields14]

its a mopar performance replacement hei. yes thats total without vacume advance..  i will bump up the initial. i think mallory or somebody may make a deal i can put in the dist. to bring the mechanical down. anybody here know 4 sure

[firefighter3931]

The newer MP distributors have an adjustable advance mechanism (Mallory unit) installed which makes limiting mechanical advance a breeze. There are several aftermarket distributors with the same feature as well.

The older stock/MP distributors did not have adjustable stops so you need to weld up the advance plate as Brian suggested above to limit mechanical advance. Bigger cams with increased duration/overlap respond well to increased base timing @ idle. Your combo might want as much as 20* at idle so you need to be able to limit the mechanical advance for proper tuning. 


Ron

[tan top]

, after 2004 of there abouts all MP stock replacement electronic distributors  were made by mallory , out side  & magnetic pick up  , reculator  , rotor arm all stock mopar , but underneath  mallory  mechanical advance plate set up ,  to adjust you dont really need the advance limiting keys , its possible to do it with a  cam degree wheel  , but easier with the propper plastic keys  

http://www.summitracing.com/parts/MAA-29014

as Brian & Ron said   older type with slots , need to weld & file to suit ,  although recently came across this ,  never used one , but looks a good alternative  ,

scroll down page near  bottom , part number J685k limmiter  , or just the disc J685

http://4secondsflat.com/Ignition.html

[Shields14]

alright thanks guys thanks it is a newere one i ordered the plastic keys. will let you knowe how it goes when they show up.

[Shields14]

alright guys i got the plastic keys and set the initial to 18 and total ended up at 34 probably need to bump it up a bit but it is running mucho better.