I might be able to help you with this. I've made a couple of mail-order tunes for SC conversions of F-body 3800s before. But I am going to caution you that nobody (including me) can make a really good mail-order tune for you unless they've already tuned something exactly like you are doing -OR- if you can get them scan data.
Having said that, no matter what I would want to see some scan data logs from your car once you got it up and running using the first base tune I made for you (if you had me do it). That way I could make sure the fuel and timing were safe for WOT operation.
Next question: Is your car an auto or manual?
-ryan
