At first tip in in PE I am seeing 12.8 and then as the rpms climb to 5800 I see a 13.5.
Mods are custom single plane efi (super victor)
219 219 .560 .560 cam
corvette AL 113 d port heads. bigger valves, bowl work, and exhuast ports opened up ect ect ect......

I'm thinking along the lines of 12.4 at tip in and 12.8 all across the board. Just out of curiosisty what values are some of you seeing?

 

Baseline the car, then make changes to see what the engine likes. It's all about making the engine happy, not what you want to see in AFRs. A Happy Engine is one that runs it's best, and ETs show what combo it likes.