you want to mod a chrome chassis rev G triple? that's goofy, that's a $4K amp. it's rarer than rev Fs.
I've had both. put a ge-7 in front of the rev g and take 100, 300 and 400 down a notch and a half. put 6.2 up a little less than one notch. turn level down one notch, maybe a notch and a half. Boom, now you have a Rev F, only you can turn it off for cleans.