Thoughts,opinions wanted gas porting pistons

Thoughts,opinions wanted on gas porting my pistons.My engine is due for a freshen up,over 400 runs on it.I want to try to get anouther 10-15 hp out of it.Will bee bumping compression from 12.3 to about 13.5,other than that my combo is pretty maxed out.This is a slant six that holds six national records that I would like to lower.Cars best is a 11.43 and I shift at 6200.Will gas porting help any on a low hp motor only beeing spun to 6500 tru the traps?Please,,NO drop a sb or bb in it suggestions.Guzzi Mark