listen to them! I didnt see the thread on the RP tranny oils.. As soon as I put it in I noticed that my tranny grinded when upshifting and downshifting into second (like... not being able to put the tranny in second when doing faster than 40km/h), and very hard shifts in all the other gears. As soon as I switched over to the mt-90, the tranny became silky smooth again, way less gear noise, grinding stopped all together, and I could now drop it into second at 80km/h.. and with the 4.30lsd that is right at 6500rpm in second, not that I'd need to downshift into second at that speed, but it just proves the difference.
Save that RP for your rear-end and go pick up some redline Mt-90!