How much for 71 Thermoquad?

Nascar are not using TQ carbs.
For the umpteenth time from what you have posted, I have NOT read or seen any comparison info/test between a 1971 & 1972 & up TQ. You can post as many videos/links as you like, but until you produce some info, the question will continue you be asked.....
Talking about links.......
OEMs have to consider emissions in carb design. It could be more important than power & economy, especially in later years as emission controls tightened.
Tuner, your expert & I agree he is an expert, said this in post #29 of the link you posted earlier:
'Except in the case of OEM control, max power & min consumption are usually desired.'