So I just got my new heads and cam installed. Trick flow, 11R 170s, with stage one cam. I am driving around and when I come to a stop the idle stays up around 1200 rpms for about 10 seconds and then slowly goes down to about 750 where I have it set. Any ideas why it's doing this. Its a Holley 600cfm carburetor, weiend street warrior dual plane, with a 1inch four hole spacer. I kind of think it might be a vacuum leak but wanted to see if any one else has any thoughts. With the new cam I get about 12 in of vacuum. Old stock cam was around 19.