OK here we go, I'l be breif. Have had my HJ61 with 12HT diesel for 12 yrs and fitted Ironman first up, then changed um as they were too hard and one of the rears sagged. Installed OME and never looked back, please use someone who knows their s!@t as when they installed mine they chose from several spring packs to get the vehicle riding level as several different floor pans sit differently on the road. They have been in for about 6 yrs now, I tow, camp, load up and work her and no sags squeeks, rattles or other trouble. So in short stump up the cash and do it Mate it will be the making of the old girl. Regards Johnny.