If it's the original numbers matching block and numbers matching carb along with it, rebuild it. If not, well stay away from holly they suck... But id rebuild it if it were the original carb for reasons relating to value.
But what issues are you exactly having? Have you checked fuel filters, checked if the fuel pump is still pumping and not shot? Checked the fuel bowls in the carb making sure it's getting fuel?
She runs just fine once it gets warmed up runs like a true thoroughbred
And yes its a real numbers matching gt 289. My grandpa bought it new off the lot. It was a one car owner until it was given to me Heck the ole gal is 50 years old this year
Sounds like it needs adjusting, running a little rich maybe? Also sounds like the fuel pump isn't pumping sufficient amounts of fuel, the fuel lines may be plugged at some point or the fuel pump is going out. I'd check the lines fuel filter and I'd take the carb off and inspect it to see if it's dirty and adjust it if you know how to properly adjust carbs. Also check your spark plugs and make sure your distributor gears aren't worn out allowing the timing to go to whack.
It is on the rich side. New fuel line, new points and plugs, carb is clean. I have adjusted the carb but I cannot find a happy medium. I never thought to check the fuel pump. I think it's getting fuel just fine the throttle response is there. If you want to be a hard a.. and pin the gas pedal down there is no lag or delay