It is VERY VERY hard to break 500hp on stock injectors. Even with all the mods in the world. Of the thousands that have tried to hit 500hp on stock injectors... there have been a couple of guys that have just "barely" got above 500hp, but those graphs usually showed that it was just for 1 split second and they were never backed up at the track. I am not doubting anyones numbers... or saying it is not possible. But just not easy or cost effective.
Most guys come in the 425-475 with stock injectors. That last 25hp can be very hard and very expensive with stock injectors. There is only so much power that can be made with a certain amount of fuel. On average guys make about 3.3hp/cc of fuel as long as they have enough supporting mods and enough air to clean up the injectors... So...
(these are just the average numbers that I have seen with good turbo/injectors combos with lots of supporting mods)
stock/135 = 135x3.3= 445hp
155 = 155x3.3 = 511hp
175 = 175x3.3 = 575hp
So 155s will get you there much easier. 175s will almost guarantee it. (as long as you have the supporting mods).
If you are lucky on just really good tuning and a high reading dyno... you might already be in the 425-460hp range... but if you are going to do injectors then I would bump up the injectors a size and get a slightly larger turbo and you will easily hit your goal.
Most guys that I know love the 175/stock + stage 1 or stage 2 turbo. That will put you right in the range that you want, tow anything, keep the truck streetable, and should be fine on stock tranny and fuel.
This would be my recommendation:
Stock + KC Stage 1.5 = 425-460hp, spool like stock, no turbo whistle, makes it a little easier to tow really heavy loads. Should run very clean on an all out race tune at WOT
175/stock + KC Stage 1.5 = 450-500hp, spool like stock, no turbo whistle, makes it a little easier to tow really heavy loads. Will start to haze pretty good at WOT on a race tune
175/stock + KC Stage 2 = 475-525, will spool just slightly slower than stage 1.5, will whislte like pmax/2003 turbos, should tow just fine as long as you keep your rpms up. Should run very clean on an all out race tune at WOT
175/30 + KC Stage 2 = 500-550hp... this is probably out of your range and I would recommend a new tranny and fuel system.
I am a little biased but I would go with KC Turbos for your turbo and Warren injectors for new injectors.
Hope that helps
