I wanted to share my experience installing my newer Kidd Supergrade in the KRG Bravo as it might be helpful to someone.  I did in fact have to switch the A and B front action blocks per the instructions under the scenario of the receiver "sitting too low."  However, neither Kidd nor KRG gives any instructions on installing the Kidd rear tang.  Also, you must order the longer rear tang screw from KRG and not use the one supplied by Kidd.  First, the new KRG stock screw did not fit through the hole in the Kidd tang.  It almost fit but the tang hole had to be opened up which was annoying.  With the tang installed now it was very difficult to seat the action.  There was interference at the points A and B below.  
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This caused binding at the rear stock screw as the holes between the tang and the stock did not line up.  In addition, the Kidd hammer strut protrudes from the rear shelf of the trigger and without any play, the bolt could not be fully retracted. The internet fix for this is to mill a small dimple at that point but I still had to relieve the area behind the rear shelf of the trigger to allow the tang screw to line up.  I shot the gun at this point and it shot just okay.  When I got it back home and removed the front action screw, the front of the receiver wanted to pop upwards apparently binding on the plastic tab that is meant top provide a locking point if you don't have the rear tang, point B above.  So, I put a sanding wheel on my Dremel:
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I inserted the wheel through the top of the stock and pulled upwards relieving both areas A and B:
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Now, the only points of contact are the front action block and the rear tang.  The action drops in the stock real easy and the rear screw goes in without any binding.  I can turn the rear screw in by hand then use a stubby allen to tighten it so I don't have to remove the scope.  The gun settled in to shoot some good groups today and I like the look and feel of the stock.
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So for me, this wasn't a drop in fit.  I hope someone finds this useful as KRG's instructions don't address this.

I just wanted to add some comparison targets.   These are 5 or 10 shot groups fired at 50 yd from a benchrest.
Eley Club prior to milling back the tab in the stock:
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Eley club after:
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Then I broke in the barrel with some Tenex and things really tightened up:
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Yes, Thank you for your instructions. I also had to do this AND belt sand the KRG tang bolt as well, not much but it made it fit perfect then.

Great, glad it worked.   Mine fits and shoots great in the KRG now.