Back in 2003 when I did 411rwhp on a DD Shootout 03 dyno, and the 436rwhp on the APA dyno at PAS WesternSalon we were running stock GTS-t injectors, with no issue at cruise, in fact running 14:1 at cruise:D
We have upgraded the fuel rail and injectors to stock GTR parts, and so far have achieved 450rwhp from a DD Shootout 04 dyno. There is still plenty of injector duty left in these. We just fitted an 044 pump, replacing the Bosch 911 pump, and at 450rwhp we had to trim the fuel back over 20%.
I was planning on using the 550cc 13B injectors, but seeing as there are a peak and hold style injector we thought the GTR injectors would work better.
Hope that clears any confusion:D