a 400whp motor seems possible with 10k. Only thing you really need to do is not to take short cuts,last thing you want is for your daily driver to blow up in a different city.Trust me.

Also do not build the motor to handle only 400,boost is addicting,so make sure it can handle more.Plus you would be pushing it if you build a motor for a certain hp,and taking it to that level.

Honestly id do a poor mans type r.Gsr block with a b16 or type r head,ive seen a few break 300whp,stock!! Ive never messed with a b-series so theres not much more i can tell you.

 

300whp with just a gsr bottom end, and b16 head or itr head..lol...come on now.. and if you mean on boost with stock internals. GSR's alone do that also.

 

If it was me, I would want my block sleeved just for piece of mind. Honda-tech has a great search engine, there is also a ton of info, you just have to take the time to look.