Offenhauser 4 barrel with what carb?

Dual Purpose Set-up for 225 w/Offy 4 bbl manifold

Holley 6299

390 cfm Hollley, vacuum secondary *

Primary jet #49
Secondary jet # 52

Power valve 25R-591A-65

Idle Air Bleed .078"

High Speed Bleed .043"

Diaphragm Spring Yellow

* The good thing about a vacuum secondary carburetor regardless of brand is that the secondary does not open until engine demand warrants the extra air/fuel mixture.