Horrible MPG/Fuel odor troubleshoot

Run your finger around the inside of the tailpipes. If it comes out sooty black, you are pig-rich.

If you are running that terribly rich you probably should change the oil right after fixing the carb, and long before you work it hard. Gas-diluted oil is not a good lubricant. It does however make a pretty good fire-starter.

Holley makes a power valve plug. Sometimes I bolt one of those in.Then I defeat the secondaries, and lean out the primaries, til the engine goes lean around 10 inches of vacuum,when attempting to accelerate in 2nd gear.Then I tune the PV, for full load. Then I reconnect the secondaries, and start leaning those out. The timing has to be close to right before you start, or you may be doing some parts over again; which is kindof normal.