Compression test results
Old doesn’t mean bad and conversely new doesn’t mean good. You need a fuel pressure gauge, they’re cheap and it’s another tuning tool. On a Holley you need fuel pressure to be around 7 psi. But you won’t know without a gauge. Sounds like a rebuild/freshen up is in your future. Don’t worry they’re easy to rebuild. What’s the list number? It’s on the choke horn, or on the side of the carb.