Just fitted the speeder exhaust to day I didn't do a before dyno cause I thought it would be no trouble to swap it back, but after a exhaust bolt braking off and drilling it out and tapping it for 10mm, I am not keen to change it again to soon.
After cleaning the gasket surfaces I have opted to use hi temp silicon in place of the gaskets.
I tightened all parts just enough to hold the parts firm but not tight so they can self align once the whole system was on with all bolts just nipped up. then I tightened in this order.
1 the bolts holding the elbows to the system.
2 the muffler bracket bolts.
3 finally the elbows the head.
Unfortunately because of rust in the fuel system it will be a couple of days to get running again, I have sealed the tank inside and out and have the fuel sender soaking in rust remover.
I have taken the opportunity to fit a 10mm fuel return fitting to the sender.