the ARP'S i used were part of a kit for THE RB26, but maybe there has been an update.
the extra length of the stud compared to the original allen key bolt made quite an amount of difference to the oil the breathers would spit out on a lap at QR, ( like about a litre every 2 laps!!)
it was the only change we had made, we then cut em down & probelm gone again.