Inline 250 with Holley 390 cfm high idle problem

[jcramsey]

Just started to notice my old truck running a little fast at idle after warming up. Got a stock inline 250 with Offenhauser intake and a Holley 390 cfm and upgraded to HEI distributor. Ive never done anything to the carb, just bought it off a guy, slapped it on and it's been running like a champ. Don't notice any high idle on startup, but once its been running when I come to a stop, it is noticeably high. Was out last night and pulled into Sonic and it started to stumble a lot and could definitely smell the fuel. Got back out on the road and it seemed to be running fine again, but still had a higher idle when stopped.

Where should I start?

Thanks!