Another 318 build, and questions. (LONG)

You won't need anything to avoid detonation with 9.5:1.

If you want 400hp you willl NEED a single plane intake and some port work.

Despite the magazine articles findings, a 400hp 318 is actually really really difficult and expensive to build with factory iron heads.

(mine made 352hp but by all rights *should* probably equal or surpass those in the magazine builds.)

KB399's are good but be careful with the ring gaps. And if you DO get detonation for even a few seconds they're history in the making

The XE268 will run out of puff about 5400RPM but make really nice streetable torque.