well I'm running 1/8 scale clutch and first run strobe slipper on my ported .247 powered maxx.
here is a direct link works flawlessly but... with a hard grabing non slipping 1/8 clutch in a maxx it will break everything else in the truck that much quicker.
As far as the header mine used to rub lightly when I as running 8 shocks. (SM chassis Rc raven shock towers, old skool maxx arms) I ended up using a savage header which cured the rubbing issues. Now I run 4 1/8 scale shocks and have no clearance problems at all no matter what header I run.