-i had the tps at 8mm long. -i would use 12mm for the throttle cable cover, as it is a thick item. -i have a similar length for balance tube bolts. but if someone wanted to use flat and/or split lock washer(so as not to mar the balance tube paint and/or powdercoat), then the length would need to be added accordingly. -i would specify the type of lock washer as split type (as opposed to star type). -i only had 13 bolts for the plenum, as i separated the 4 for throttle spring covers for those with newer style plenums.