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.