Loctite is the likely suspect, especially since some appear to be partially loose yet still reluctant to budge. 250 degrees in the oven for an hour or so, then try. You can also take a cutoff wheel on a dremel and make a slot in the heads for a beefy screwdriver. But Loctite is my guess as to the problem.

couple days at the gym should help , maybe some creatine powder .

+1 on the acetone and trans fluid....

Those impact drivers are incredibly effective. Couple it with PB blaster

I did get them all removed. There was White type sealant , I tried the heat and it did help , there were a few that just said no , used a large drill bit and and took the top off , had a 1/4" or so of thread and what was left came right out.

Have the tab plates themselves to do ,so I will try the acetone/mix suggestion. Think it may be 5200 that Dana used.. So thinking that the convical surface were just bonded.

For allen head bolts I always use allen sockets by snap-on because they resist rounding

^^^^ and fit exactly...Unfortunately all tools are not made to the same tolerances and snap-on does deliver (but you do pay for it)

Being a retired VW/AUDI/Porsche/etc tech... sometimes it's a good investment to save "hours" of wasted time to do the task? After all it's only $25/week for life(LOL)!