Holley 390 4bbl on my slant 6?

I have an Offenhauser 4 barrel intake that I have been debating on installing on my stock '75 225 in my Scamp. I'm not expecting a HUGE performance gain, but I'd like a noticeable change to the 1bbl.
The motor is stock and runs great with larger single exhaust and a Cherry Bomb. It's a 904 with a 8.75 3.55 rear in it.
I've seen people say to go with a Super Six 2bbl set-up, but I already own the Offy. Is the 390 cfm too much for a stock motor?
I would appreciate any experience you guys have with a 4bbl set-up on the 225. What did you use for linkage - both throttle and tranny kickdown? Was it worth the swap on a stock motor? Thanks guys!