My 422 smallblock build

If the carb is an old school 650 that doesn’t have 4 corner idle, then yeh………it’s probably going to be a challenge to get it happy idling in gear.
Yes, it is an ancient 650 without 4 corner idle. Most likely late 70’s-early 80’s vintage, so it doesn’t disappoint me that I need to step up to something more modern. The car is a 4 speed so in gear idle isn’t relevant but because of the small throttle bores and the size of the engine and camshaft, I’m pretty sure it’s trying to pull on the boosters at idle. I’m gonna look for a deal on an 850-950 with no choke horn before I spend too much time trying to tune this thing. My heart says Holley HP but my wallet says Proform.