Id say if that's the power your looking to get to, the s300 would the way to go. Not so much because its impossible with a hx 40 but it would be eaiser and you wont have to worry about breaking it. And id say 400 would be pretty possible with maxed pump and all supporting modifications.
just curious what kind of milage do you get with your setup?? 1BAD93
i run the he351 and am putting in 6x16's next...if it gets to hot ill water meth it untill i get twins figured out.
with my pump @3/4....screw stock rotor.cam and the he351 it will hit 38psi wasgate welded shut.
maybe hitting 350hp if iam lucky.........that 400hp is a big jump.
I've seen a truck with custom 435s and a gds 60mm wheel kit on a stock h1c and alot of timing make 390hp. So I would say with a better turbo that same setup would well into the 400hp mark. Not saying this is the greatest setup or anything like that, its just I know for a fact its a proven setup. I also know with pods and a maxed pump and box stock h1c they'll make about 360hp.I'mwanted to know what injectors and turbo for around 400 hp?