Everyone I know with 80s (I have never ran into a set myself) are using stock offsets. The injectors are fast enough that stock settings will be more than enough to handle controlling them down low. If you have the paitence to deal with the minimum injector pulsewidth values, then I would consider playing with them for a bit based on how different they are from stock (you will need stock 33# injector data measured in the same way the 80s are if you were to calculate anything).