Double Spherical bearing all the way, 100% adjustment & security of a locking nut! Slotted works, but is less accurate IMHO. I have a Adrenaline beam on the Escos, and a Zoo beam on the Saff. Have to say I'm VERY happy with the Adrenaline one, very easy to adjust & lock off, had no problems at all getting the Camber & toe I wanted, with all the axle offsets correct & thrust lines correct. All the threads are well in safety with plenty of adjustment left either way.

Zoo beam is not the best quality ever, I would describe the welding as "industrial", and I threw away the crappy Alan key headed adjusters, and made some 42mm (don't ask!) barrel adjusters & locknuts for it, which has made it lots easier to adjust. It also has the Jag diff conversion, so I can't complain for the song I got it for .

The other two things that are VITAL to do is solid mount the massive car to beam joints, the standard ones are shockingly compliant as standard, let alone after 25 years of thrashing, environment & zero maintenance. The other is to fit a poly rear diff, as supplied by Rainbummer or MSD, it makes a world of difference!

For the non believers, jack your car up on the chassis, and get a mate to pull the rear subframe from side to side with you. You will find that the back end moves around like a fat birds arse on a bouncy castle!! The toe changes are scary for a standard beam, and then on top of that you have uncommanded movement from the bushes, I wouldn't be surprised to see over 5 degrees of toe change through the movement! No wonder most cossies feel loose at the back

Rainbum put some figures up for the modded beam, I will see if I can find them.

R4N S, you are doing EXACTLY the wrong thing, beam should be the first mod anyone does!! Everything else is wasted until you can put the power down properly IMHO!