OK
I took a closer look at the injectors today. There is nothing else but maybe this helps:

This is from the RACETRONIX website-
Part Number Delphi 01D030B (Lucas old 5208009, Lucas New 621031, Delphi old D3181AA) ???
Maybe you have worked with some of these?

Regarding pulse width, I screwed up in my previous post.
I am seeing injector pulse widths of 19.5mSec at 4,000 RPM (this is with 10psi of boost). this puts me at a 67% duty cycle.

Here is the quote from the LS1edit doc regarding the offset table.

"4.2.6 Injector Offset
The injector Offset Table is used to compensate for the time delay in opening the injector. This is the base time used for every injector cycle. The calculated Pulse Width for the needed fuel is added to it. It is in Milliseconds."

My understanding from reading this is that the offset will impact both the length of the pulse and also the timing of the fuel delivery.

The question is how much faster are these injectors than the stock Bosch type and is it something you have ever had to worry about when tuning?

P.S. No answer from Racetronix yet, but their sales team are out of the office this week

Dave