pre burnt chips if done right for your setup will work close to right, and depending on the system, you'll have active fuel trim, which will run off the tables in open loop til she warms up and then try and base the fuel trim close to the table but also run 14.7:1 AF ratio.... the problem is on the systems that are burnt to run stricktly off the table in open loop, they dont accomadate the fact that engines built 500 times with the same parts aren't going to run exactly the same, plus the weather and altitude can change effects too..... i reccomend if you want to do EFI make sure your system is going to allow closed loop with fuel trim capabilities..... and reprogrammable fuel tables... and its even better if you can use a fully electronic ignition so the computer can control advance as well.... maybe even a distributorless ignition.... thats why i'm thinking of building my own coil on plug system.... i'd reccomend maybe taking an ASE engine performance levels 1 and 2 classes at a local college so you can really get the theory