I've fitted K&N cone filters and Predator pipes. My main jets are 138, with perfect fuel/air ratio. The needles have been raised by one shim. 71 rear wheel bhp, but thats with gas flowed and skimmed heads (10.4 - 1 compression ratio).
Yes. The head was gas flowed, ported and skimmed. The work was carried out professionally by a local engine tuner.
I've seen the short ones with the BellaCorse or Newbonneville adapters and they looked good. I've heard also that they're LOUD but you can always use the 4" long J.C. Whitney baffles(part # ZX013522R) up front in the adapter pipes. I didn't check the web site but make sure the mufflers come with the adapter sleeves to fit to the adapter pipes coming off your headers and use high temp silicone for a good seal. The J.C. Whitney part # ZX017567P shorty seamless megaphone muffler is probably the same one you're talking about. Read the reviews at their web site.
