Hard to grease...what is going on??

[72timemachine]

I have an 84 1 ton GMC and after replacing the upper control arm bushings... or dog bones, it seems just the grease fittings toward the firewall are crazy hard to push grease into. I have to squeeze the grease gun like a nut just to watch the handle compress a 1/16 every two seconds.

I did check the fittings by removing them and pushing grease through them but that does not seem to be the problem. I even greased it fresh off the road thinking it may help if a bit of friction (heat so to speak) by movement may allow the grease to flow in a bit faster but no dice.

What is the deal? The front ones and lower ones grease up with no effort.

Thanks for any help.