The 4972/4973 TQ is a one year only design with one year only gasket/rebuilt set. They are an air bleed design (all 72 and later are a solid meter design). The 4972/4973 TQ's do not have the glue in bowl parts or the O-rings mentioned above. Fuel purging from the carb is almost always a float related issue, sunk or not adjusted right. A fuel blockage somewhere from bad fuel is a VERY common cause (needle/seat, etc.). Also check for weird stuff like a mud dauber wasp nest clogging your vapor return line if so equipped.

One good source for gaskets is www.walkerproducts.com, they may have to put custom kit together to accommodate your 4973 carb.

*Or, you could send it to me to restore for you