Have a 289 with stock heads (54CC). I want go to a ported head with 1.94 and 1.60 valves. If I go to a 351W head I'll lose compression but gain flow. If I have my 289 heads reworked I'll keep compression but not have as much flow as 351W's. With shaving how low in CC's can a 351W head get. Should I go with my 289 heads or get a set of 351W's.