Thats why I suggested a call to the good Doc to clarify this. Any axle will fit a suregrip unit, which has no bearing on the thrust button, which is in place in all 8 3/4" rears to set the endplay. It is when you use the Green style bearings, which have no adjustment needs, that the thrust button is usually removed. I don't believe this situation was addressed when these bearings first came into play, and maybe this situation was recently addressed by Dr. Diff to make taking apart the rearend to remove the thrust button unnecessary.
Just like our original poster here, he would like to slide out the axles and replace them with a different unit without changing anything else, and I don't believe the aftermarket has conquered this need yet, especially if he is planning on running the OE 1 3/4" brakes, which are not drilled for 4.5" BP, hence the need to change the brakes also. Alas, I think the answer for our friend HemiTM is either a complete change of axles, tube ends and brakes or OE style SBP axles with the proper backspaced flange for his 1 3/4" brakes, if that is what he is currently running. Maybe a message from Hemi on his brake setup can help solve this for him!!! Geof