I have been procrastinating about changing the rear axle on my 48 8n for a 52 8n rear axle with the better 2 seal trumpets. I have the complete rear axle differential from the 52. I have been contemplating changing the entire rear end or just the trumpets and axles. it appears the left trumpet has the bearing retainer for the differential. is there a concern about getting this together right? The 52 has good brakes, but i still need to pull at least one axle to get the shims right if I just change the trumpets? I rebuilt the 48 in 1975 and the brakes worked well for 20 years. any advice or concerns?