'wrench....dyslexia kicked in on the numbers, but the "regular" predator is 68120, the big valve motor is 69730 and the hemi head is number 60363 (got the box in the shop). i don't know if my explination of the pop up/out is right or wrong. but it seems that the rule is either obsolete because of the head rules or the mystical magical reason for having the rule is to be held secret by the brotherhood of wka/akra. a rule that is either obsolete or made null by another rule (ala the head/combustion chamber rules) should not still be there. this is the problem that several have tried to get across to the sanctioning bodies....that the rules package isn't being rewritten or updated, it's only being added to and the obsolete, redundit or erroneous rules aren't being cleaned out. i've read what dynodon has put up for the rules package and i like them....easy to follow and understand...but it needs to go beyond just the motors....a rules package should also have safety, tech procedures, racing venue procedures....all of it...this is one reason that i'm an advocate of putting all the rules online and either letting everyone see them or offering them as part of a membership fee. either way...it gets the rules out there and they are easily modified (additions or deletions or to further explain). instead we have to kill a bunch of trees to print a book...i ain't a tree hugger, but dang! if you have a new tool that does the job better, easier and faster, then why are you still doing it the old fashioned way? reluctance to change and avoidance of stuff that you can't understand...that's what is keeping things like kart racing in the dark ages.