And they will not cause headaches too! I've built around 10 cars Over the years with headers. I'm sick of them on street cars. So with 350 hp it's not like it's costing me 100hp. If it is, oh well. I'm just done with them for daily drivers. I'm hoping for 335-350 crank HP. More is icing on the cake but I don't see it being more than 335 or so.