have got a new vibration damper pulley arriving tomorrow (pulley attached to the bottom of the crank by 4 studs)....i took it on and off last week using torx fittings but have been told i should use spline fittings....going to buy one individually from machine mart but need to know what size

then this weekend going to clean the egr,boost sensor and do the air filter mod....need to enjoy driving it again after forking out over a grand last week (dmf,clutch,tensioner belts etc)