dont forget as you change the jet size you need to change the (and I forget the industry term) but lets go with aperture (the holes the gas flow venturis air in through ) and the spacing of the nozzle. as well as the pressure regulation of the gas.
(small stuff it doesnt really matter but if its a big unit with the changable nozzles , aperture slides and threaded seat guide its got the adjustments for a reason)

