From what I gather from your posts, you are using a '96 up vortec (L31) engine. If so, the heads etc are going to require more Acceleration enrichment (both tps and map based). The VE tables are going to be somewhat different that a standard tbi engine. The vortec heads also will want more spark advance than a normal tbi engine. There are several threads on here that cover some of the differences. I am on my smartphone at the moment and it is inconvenient to search and paste some links. I can send some links when I get home from work this evening. You can use google search on the site by typing site: gearhead-efi.com and then what you are searching for. Look for L31 spark tables and also for threads on AE
Hope this helps,
Brian