Thanks for the kind words Brian. I really should start saving or selling stuff for some twins with all this fuel.
Rebel, everything I have done has been bolt on as Brian said. It should get you to 450hp. Keep in mind as shown by KTA's VE, not all pumps are created the same, act the same etc. Of course reliable HP... that depends on what you call reliable. If it's towing a 28k lb trailer, I don't know how well or long my setup would stay alive. I'd say to atop the get on ramp LOL. For daily driving, cold starts, highway trips empty running etc, it's worked fine, knock on wood. But some of the 14mm pumps haven't fared so well.
As KTA has always said the biggest HP increase or best thing for a 1st gen is INJECTORS! POD's are good if you think 350hp is ok. DDP's offerings seem to have not gotten the job done either in some of the other big dog's trucks. For the price, work, tricks, and detail in these Buddha Power injectors, I don't think you can go wrong. Not to say I didn't like my Scheid injectors. But after speaking with them recently and finding out what they DIDN'T do to them etc, I could've been better off and money ahead with these Buddha injectors.
Don't waste your time on the so-called 4200rpm spring. I think PDR seen some of my comment's/posts about my R&D with a stiffer, longer higher rpm spring and how they should be ashamed for selling them to 1st genners. Shortly after some of my posts, I see they took them off their website. Of course they could just be out of them though. I ran a 3800 spring. It's stiffer, longer than stock and 366 and same length as 4200. 366 is stiffer, but the same length as stock. You have two choices how you could run a 3800 or 4200 spring. As is, or trimmed to stock length to fit properly and not possibly hang up inside as '92-Dunit's' truck was doing. I could go on, but I covered this in detail on DTR and I'm tired LOL.
As KTA said, you're not making much if any HP above 3500rpm. Look at his dyno sheets on diesel-central. His HP fell off at or around 3200rpm and he just choose to continue to run the engine out to 4200ish rpm and 200mph or so
. Since he was making so much HP at 3200ish rpm, and his engine is King Kong, this is the reason he was still making 350hp at 4200rpm... SHOW OFF! Most of us can't make that at 3000rpm, let alone 4k+
.
Seeker, injectors, upgrade 1/2"ID fuel hose from tank to pump, 3200rpm spring, and then do something about your turbo(s). Then again, you might be just fine with that 55 setup, just need the fuel to do something with them.