Jeff's 727 rebuild thread
Lots of people toss the spring however the research I have done suggests that it should still be in there. I have tossed them on quite a few builds but now leave them in. If you want the spring let me know and I will send you one. If it has a restrictor in the main case as I mentioned above (looks like a small steel cup with a hole drilled in it) it has most likely had some form of kit put in it. Also, when you open up the valve body, if you see the one hole has been drilled to join two passages (your transgo kit has a drill guide for this) it is a dead giveaway that it has had a kit put in it.