318 with 675/318 or 974/360 heads Cam Recommendations

Here is an alternative for you to maybe get around any re-balance work......

• Use the KB399 domed pistons with are 26 grams heavier, and in a .060" oversize will be getting pretty close to stock weight
• Use the 360 heads unmilled

Now your SCR with a 1008 head gasket is 9.6.... pretty good and will further help with your altitude challenge for dynamic compression. With the 256 cam, the DCR is 8.1 (equal to 7.3 at sea level) so you now can increase the cam to the 262 (or perhaps even a step more) to better use the breathing of the bigger heads .