Buttonhead Screw Mod for D27 Knuckle

I was doing the buttonhead upgrade on my D27 knuckles last night and ran into what appears to be a problem. The first knuckle (I only have one off) looked fine. Not a lot of casting flash around the hole, and I was able to grind it off easily with my Dremel. However, when I began to screw down the buttonheads, I noticed that here did not appear to be enough room for the top two to screw down flush due to the way the casting is made (ie, there is a "lump" inside that is part of the casting that would appear to be designed to support the knuckle bearing. I don't have a camera right now, so bear with me. I didn't see anything in any of the write-ups that indicated any grinding there. In fact. M. Ludel's book was emphatic about not weakening the casting. I don't know if this is casting shift, or simply a fattened inner knuckle on a relatively late D27 (1970)

So, my questions are these:

1. Anyone ever encounter this problem?

2. If so, what did you do?

3. How important is this mod? I know what could happen, ie, I have read and seen the results of knuckle bolt pull-out. But with what frequency does that occur? This CJ will see some off-roading and is fitted right now with 33x 12.50s. FWIW, the knuckle bolt threads are in very good shape, doesn't look like it has been apart since 1970.

4. Would the "drill and press fit the stud" method also encounter this problem?

 

I think you need a spot face chucked in a drill press set at its lowest speed with a little bit of cutting oil.

 

Do you think that would open up enough space to run the screw down? this is not a chunk of flash, rather it is an intrusion from the side, not the bottom of the knuckle. Hard to accurately describe without a picture....

 

When you do these with studs, you drill the holes out to 3/8" and then use a counterbore to flatten the surface off so the stud will sit flush. I have never done them with button head screws but the same problem still exists, its core flash from the casting and the surface needs to be flat for the screw to seat properly.

 

here is a view I just sort of drew up....don't laugh....

 

You know you can always grind the head diameter of the button head.
I really need a photo to help anymore.
Oh got to say, I love your stick drawing.R)R)

 

I know, I will try to get some pictures tonight....

 

here is an excellent write-up with pics
http://earlycj5.com/tech/steering/knuckleStud/index.php

 

Here's a pic of my studs from the back side. You can see the spotfaced area for the head of the studs.