I did some reserch on that pete jackson gear drive and it does have Retd/Adv.marks.Iwas also told gear drive takes away 8-10hp! So I'm replacing it with a good double roller. And ya,that spacer is gone! Now,to formulate the right thumpstick.
I had very good luck with the XE284H with 9.73 compression, ran 10.9s all day long & the cam was on the milder side as cams would go for the torque it produced, then i went with the Comp 282 solid stick (i think that was the core) i've slept since then lol, it was there .520/.540, had Comp custom grind the core for the lift/dur. i wanted, made it a .529/.543 & .250/.256 @50 on a 108, car still ran 10.9s lol.