It's a Holley 4150. Pretty common carb. 650cfm. PO stated it was a 750 buy my research shows its a 750.
It's doing a bunch of different things.
Ran well before. Meaning, we turned it on, drove it around, it didn't die, didn't run ideally but didn't die.
Now, I'm trying to follow instructions from the interwebz and sometimes it'll idle correctly, sometimes it seems like its leaking vacuum somewhere, sometimes it seems perfect then you put it in gear and it dies, then it's running ok but you put the air filter on and it dies, etc.
Can't get it to just be right on all aspects (idle, curb idle, while on the gas, etc).
We rebuilt the carb, so we knows it's all good from a parts standpoint, and knew I was in for some fun in tuning it, but didn't expect it to be so frustrating.
I'm not kidding, if someone can come check this thing out, I pay cash.