I understand your statment now. The tension of the heavier gauge strings was pulling your bridge forward. By placing the shim in between the trem block and the body cavity it relieved the stress of the string tension.
This still would not correct your action height. (I am not trying to demean you in any way, I am trying to help trouble shoot your problem and come up with a solution for repair. That you may do yourself and not cost an arm and a leg).
A possible solution to relieve some of the string tension on your bridge would have been to tighten the spring block screws drawing the string block closer to the body. (you don't need to now do to the trem block shim).
This would have pulled the rear of the bridge back towards the strap end of the body lowering the bridge rise.
If your looking for Fender specs go to their website @ fender.com. There are free down loads and tutorials.
I suggest that you drill a hole (1/8" diameter) in your trem block shim and get a sheet metal screw (about a # 8x 7/8 inch, about a buck at Lowe's).
You can screw it in when you want to pull your trem block out. If it's a tight fit you don't want to pry it out with a screw driver and chance damaging your guitar body.
Good luck,
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Bootlegger guitars.