When I went looking for one I asked Rodney for a picture of the correct one (I think he has pictures on his site now). My early 86 actually had the right one already, so the exact time the change was made might not be as clear cut as 87. Or mine got replaced before I bought the car.
------------------
10.007 @ 135.54MPH. <-- Video
Best 60' 1.42
Best mph 138.82
Billet 6262 Precision turbo, PT1001 intercooler, ST1 cam, 140lb springs, comp pushrods, HV3, stock L32 bottom end and heads.
Old M90 XP Cam time -
11.425 @115.60
1.543 60'