[Diy_efi] fuel injector limits?

[Charles Woock]

I've done the math... I used a desktop Dyno to get as close to my motor as I could (many hours of tweaking), and came up with 270 hp (in my 4.1L Buick V6 race motor).  The math says that a 24 lb injector is right at the limit of 270 hp.  I have several questions about this.  

1. I'm guessing that the desktop dyno will show a little more hp than I can actually get, right?
2. Injectors that are too big cause problems with idle and lower rpm tuning etc... How much bigger is "too big"?  Will a 30lb injector be too big?
3. I found a 27lb injector at fiveomotorsport.com but I don't know what pressure that rating came from.  Thoughts?
4. How long can you run an injector at 85% duty cycle before it starts to get wear out.

Last and most important question.  What do I buy 24#, 27#, or 30#??  

I'm currently converting it to EFI using a 1227727 and 3.8L MPI intake.  I like a challenge and the details of this project are definitely challenging me.  Details, details!   Thanks!

Charles