Ok today i messed up a perfectly good e31 head, I over unshrouded the Intake valves #5 and #6 and the middle where the chambers separates is about 4mm apart. Is that too much? I got grinder happy i guess, what other head can I use on my L24 block that would be a upgrade? I have a 17034 schneider cam 460 lift will a 280z head clear the pistons?