Wondering wich would be better bang for buck on a 670 ho. stock they say aprox 125-130hp will i get better power for dollars from a set of pipes or a big bore. i have been looking at pipes and they range from 450 to 700 what does a big bore cost? I am able to do assembly stuff but will need parts and machining done for me. what is tuning like after if i bore it out? i know pipes can be a real pain in the backside. thanks:d