thanks for the advice guys. Jelly that was a helpful article also
though i should clarify. im not getting this built by palmers. im going with someone else and they dont offer the .685. the size i can get is .686 ....i know, not a big diff but i dunno, maybe worth re-mentioning. I will be tuning this thing and using palmers guts though so i hope your wrong about efficiency stilgar...i hope.
anyone have any other advice? the more the merrier