Not to throw a spanner in the works, I know this is about N/A and what not. But to back up other statements mad about good tuning (which I know we all know about)

"Not planning on sleeving the block. The stock sleeves are more than sufficient for our power goal of 600whp. Jeff has done close to 600whp on b-series with stock sleeves, so given that these sleeves are 30-40% thicker and the whole bottom of the block is girdled, it's much more tortionally stiff." The motor in question is a STOCK TSX longblock. K24(?)
Taking from http://www.k20a.org/forum/showthread...3&page=2&pp=20

Again, I know its turbo not N/A, therefore a little off topic... BUT ... it shows that with that much HP good tuning can eliminate a cost. ie. Sleeves...It also states that a K series has better sleeves, again, STILL going to make more horsepower.

Apologies if post is off topic or didnt make sense