what lmp are you running the gas at on the tig. i have found that you can get away with about 4-5lpm on a no5 or 6 ceramic welding the chassis. saves quite a bit of money on argon
i did tig quite a bit of mine. but like ronnie i get fedup and crack out the mig as its loads faster and easier to get into all the tight areas with a slightly crushed gas shield