If I remember correctly the solenoid is mounted to the same bracket that the MAP sensor is mounted to, and that mounts to the intake on the passenger side by the throttle body. There will be a nipple on it and the plug is green if I remember right.
It may run fine now but I doubt it will once you get the heads on there. You should have a chip burned for it but that takes time and money if you are going to do it yourself, and money if you have someone else do it. I had a similar setup but with other variables that made the mail order tunes not work for me. You may be able to get something that works going through Brian at www.tbichips.com
. I would at least visit the website and check it out to see if that is something that you want to do. The other option is to find someone locally that does it, but it's usually about $1K because of the time involved.