I am having trouble setting timing with my new mopar preformance dist. with my old dist. base timming set around 12 and total was about 38 and i had about 15 in. of vac. when i install my new dist and set the base around 12-14 total timming at 3000 is only 24 went on up to 3500 and there was no timing change and vac. is only about 12 in. is 10 of cent. advance all i should be getting? all testing is with vac. advance unhooked

Check out the other thread on this, the new MP distributors have an easily adjustable plate under the pickup plate. Take off the reluctor/vac can/pickup and you will find the two torx bolts. Easy to figure out. If yours has the one light spring and one heavy I would remove the heavy one and just run one light. I got all advance in at 2500 that way. Also, I wouldn't be surprised if you have more advance than you think because I had to reve past 4500(!) to get full with both springs installed.
You will probably have to trial and error on the adjustment till you get what you want.

You also have to set your idle really slow to check base timing,the mechanical advance starts coming in very early on these distributors(I installed These on two 440's three to four years ago,new ones may be different).It may be esier to set your timing around 36degrees at 3000 rpm.

when i set my timing by total timing I have low vacuum about 11-12in at 800 rpm the cam I have was a cust grind from comp. to give 15 in of vacuum to pass my class rules the only way i am able to get enough vacuum is to over advance the timing and with the new dist it still doesn't pull 15 in of vac. but when i switch back to my old dist it will pull 14.5-15 in of vac. with about 18- 20 deg. base timing but that makes total timing 48 -50 which i believe is to much i tried the small spring removed and it did help bring timing in by about 3000 rpm but still can't get vac. thanks for any help