I was just going to leave my not worth the money comment stand for it's self.But after hearing the claims of increase %s I must comment further.Years ago we had a local racer peddeling the extrudeahone process.Butch Palm was the racer that I recall,anyway we got caught up in the action and had a set of manifolds(intake and exhaust)done for a 440 it was very pricey for back then.The car was a dialed in 440-6 cuda that ran low 12s consistantly.After the process the car lossed a tenth.We struggled with jetting and anything else we thought was effected with no results.We replaced everything back to stock(manifolds)and regained our loss tenth.Was it worth the time and money?Heck no!