4bbl

Something to keep in mind.
A 600 Holley 4 barrel (1850) and a 350 Holley 2 barrel (7448) have the same size throttle bores.
A 350 works quite well on a 225, therefore, the 600 should too.
If the secondaries are not required, they wont open.
I have a 600 on a Clifford Hyper Pak, with headers, a 2"exhaust, on a stock 225 slant. Not ideal, but drives just fin, and goes way better than stock.