Not really think about it stock 350 with stock airbox remapped lets say is 270bhp, if thats the best then why would you gain from a worse set up? otherwise with stillen you would be lets say for example 272bhp. The stillens would also get gains if and only if worse induction system was fitted before e.g. pikey ebay filters with no heatsheilds and the like. If the stock system is the best and you have a stock sytem then how can you get gains
Agreed with above I run a k&n typhoon and it sounds wicked.