Correct,
An early Thermoquad is not for the 'Average Joe'..........
You need some patience, and experience to dial them in.
The 1972 thru 1974 'solid fuel metering' Carbs are the most desired,
for bolt-on performance units.
1972 Series
* 6138S > 340/240 HP {M/T}
* 6139S > 340/240 HP {A/T}
* 6140S > 400/255 HP {M/T}
* 6141S > 400/255 HP {A/T}
1973 Series
* 6318S > 340/240 HP {M/T}
* 6319S > 340/240 HP {A/T}
* 6320S > 400/260 HP {M/T}
* 6321S > 400/260 HP {A/T}
* 6324S > 440/280 HP {A/T}
1974 Series
* 6452S > 360/245 HP {M/T}
* 6453S > 360/245 HP {A/T}
* 6456S > 400/250 HP {M/T}
* 6457S > 400/250 HP {A/T}
* 9015S > 440/275 HP {A/T}
Next choice, would be the 1975 Carbs with the {IES} and {TPS} contraptions,
which both can be removed.