Hey guys I need some help. Today on my drive home I noticed when I let off the gas I was getting 30 inHg of vacuum. My idle is around 18. I got the car back from putting in my new tranny recently and replaced some of the rusty clamps on the ic piping. The only other thing I did to my car today was change my oil. I accidentally put in 5 quarts but drained some out. That shouldnt have affected my vacuum. I have HKS 264 cams as well. Any help is needed as I just wanted to make sure it is alright and im not stressing.

 

18 inHg at idle is normal for your setup. When you let up on the throttle, in gear, the motor is still spinning at speed and trying to draw air through the closed throttle. So you will see a higher vacuum than if you were idling in neutral. Your readings are okay.