We offer a service that involves cutting open and gutting the offy intakes for the nailheads. Otherwise they are unusable. Intake shown robs 60+ hp Before gutting. the loss is relative to what engine its on and in in comparative to what other set up.. Even after the service they dont hold a candle to any of the other aftermarket intakes, so take note of that. The tripower robs easily 100hp from these engines (compared to an 800 on a stock four barrel on a late engine) and litterally turns the engine into a 6 cylinder. cylinders 1 and 7 get about 20% flow with progressive linkage prior to WOT.
Take note that cutting the top of the intake is only a portion of the work. We then go in with 6 inch long stem rotterie files to get the bottom cross overs that involves gutting holes in the side of the intake and welding it back up. Good service for a couple hundred bucks. Tri power is a little more money and the gains arnt as much because the intake doesnt have as much meat on the bone. Call us. 530 272 1564.