Originally Posted by wantboost

Yea that's also something to consider. The VTEC heads tend to deliver a wider powerband due to their efficiency, port size, and cam profiles. Although part of me has always wanted to put a P8R head on a high compression B16 bottom end and rev it to the moon for ***** and giggles just to see what kind of power it would make NA and then maybe toss some forced induction at it. I have weird ideas sometimes.

Originally Posted by wantboost

Stay away from rocket springs.

While 400hp is achievable with stock cams it will take a lot of boost pressure to get there. Are you positive your turbo will still be efficient and operating properly at 25psi or so? Aftermarket cams will greatly improve power production although ultimately the cylinder head itself is going to limit power production and make reaching high hp levels very difficult, mainly due to port size and flow limit.

Remember that LightningTeg had to run something like 34psi on his built ls head to break the 600hp mark. You could always try and source a P8R head but given how rare and desirable they have become by the time you find one depending on price you could have put a vtec head on your motor and made more power using less pressure with a bone stock vtec head and cams than you could with a built ls head. Why do you think Lightning is finally moving to a vtec head?