I'm gonna tell ya right now, as fellow Regal owner with a Buick 350, don't try and use the Buick 350 as a selling point, no one cares. If it isn't already hacked up with a Chebby 350, no one really gives a damn. Even if it didn't tick, first thing people will do, guaranteed, is rip the Buick out and put a Chevy 350 in. I guess they don't like a lightweight small block v8 that makes big block torque with an easily accessible distributor, or awesome sound. Go figure. The tapping noise could be a broken rocker button, bent rocker (stamped steel rockers), or the front cam bearing has wear and is partially blocking the oil feed hole. On 350s (maybe 455s, and 231s as well) a tell tale sign of oiling issues is driver's side vt noise.
That being said, sounds like you have a very nice roller on your hands. I'd be surprised if you couldn't pull 5k out of it as it is right now. If you still have the T Type/T wheels, that's a selling point if they aren't beat to sh*t and have the center caps. Plus I mean all the suspension mods, an O/D trans with the dual pattern bellhousing, 3.73 posi... yeah. You got a nice setup there... why are you selling it? Bored of it?
That being said, sounds like you have a very nice roller on your hands. I'd be surprised if you couldn't pull 5k out of it as it is right now. If you still have the T Type/T wheels, that's a selling point if they aren't beat to sh*t and have the center caps. Plus I mean all the suspension mods, an O/D trans with the dual pattern bellhousing, 3.73 posi... yeah. You got a nice setup there... why are you selling it? Bored of it?