When I first start my car it idles around 525 to 530 in mmHg on the safc II. After I run the car for a min. it drops the pressure down to 480 to 460? Why is it doing this and is it hurting anything?

so its dropping from 20in/hg to 18.5in/hg? (not sure if i did the conversions right...) During warm up the idle is slightly higher and pulls more vac. Either way mine idles at 12-13 in/hg and if i turn the AC on it drops to 4-5in/hg so I'd say you're in excelent shape and I should be the one posting about a problem...

Thats sounds good. I just thought that I read it was susposed to be around 525 after warm up. Well I am about to have to take the head off AGAIN because I have a leak on the back side of the head and I am only pipes away from my custom stage 2 kit. It only takes one stupid mistake to learn grave lessons.

Also when I am on the highway cruising at 75 and let off my vaccume goes to 25? Before the hg it only went to 18-20. Still normal?

If you're basically stock, those numbers sound about right.

Yeah stock vacuum is approx anywhere from 16-20 hg's. Any lower than 16, then its either a timing issue, or a misfiring/dead cylinder..

Well I have AEM V2, 4-1 header and downpipe, 2.5 catback, and AFX udp. Not sure if that makes a difference. My timing should be dead on, because I just recently did a hg replacement and messed the timing up the first time so I had to reset the timing. So the second time I quadruple checked the timing by rotating the crank by hand and checking the alinment on the cam gears.