I think its 171-175cc? I'll have to check the pair here. Definitely 170's cc, 2.02 240'scfm
Ootb
Fwiw for comparison
Stock 318 124cc 175-180 cfm
340/360 head 155-160cc 197-228cfm
300-350hp goal? That's a 5500-5800rpm red line motor imo. Excess port volume only hurts this build.
That's how I'm looking at it