65 barracuda 273 commando

On throttle bores being too small on the intake, why not use a file and correct any interference? You should also look at the street demon carb., if using for daily driving. It is corrected for todays gasoline, which is different from 10 years ago. Try to avoid adapters if you can. K.I.S.S.

Look at rebuilding by Harms, it sounds like several people are happy with his work.

And Yes I have ground intake bores too avoid using adapters and was pleased with how everything worked out, but your mileage may vary from mine.

Good Luck, however YOU decide.