that # goes way back, way before I got going with Tilly carb's in the mid 80's but, if it's an alky carb from the factory, it should have a low side needle that has a blunt tip, the gas needle has a long taper down to a sharp point and a screwdriver slot to tune it. Also the low side needle hole will be much bigger than the size of a gas carb. Gas carb about .040, alky around .070. Under the welsh plug the drill pattern of an alky carb is much bigger. A typical gas pattern would be .034 air correction, .040 intermediate, .028 idle circuit. All the alky carb's I've seen had a three plate stack on them but that may have come later on. Jon
