K, I have the side exhaust version, when I got it I couldn't keep fuel at the carb, it turned out that the banjo shaped fitting that's bolted to the carb and serves as the fuel inlet was too large and air was getting in around it. I'd just run it with the pipe and header the way it is because you can't set the header length until it's broken in. It won't take much breaking in. I broke mine in on Fox 5% nitro fuel with 20% 50/50 lube.