Make sure the car was born with that engine. I believe there was a year or two where an off the shelf intake won't fit on some 273's . Swapping intakes and carbs also throws off your kick down linkage. Guys on here have what you would need , whitepunkonnitro comes to mind.
That said , we had a solid lifter 65, 273 2bbl single exhaust barracuda. An absolute blast, I split the brakes for safety and performed a complete tune up as suggested. It was quick, torquey and fun. I miss it lots.
