The bar that goes up and down is called the metering rod tree. The rods hang on the ends.
You can bend a AFB rod 3/4 or an inch shorter and clip the ends off. The rods are thicker than TQ rods. This is a problem to use on the smaller holes on the metering rod tree. Adapt and overcome!!!!!
If the bottom well cap under the jets ever come off & you have the good luck that it didn’t break, you can re-tap the TQ jet threads for Holley’s jets. (FWIW)
The Holley jets will need minor mods.
Address your weak spark. Up the coil power output. FWIW, a multiple spark box is very good for the low cruise rpm’s. & to help with a cleaner idle.
As mentioned earlier, the TQ was born a race carb, not an emissions carb. This is fact. They made there appearance in ‘69. 2 years before they were stock components.