Ever change cab mounts?

[bigmoe]

My squeekedy squeekedy truck is driving me nuts. It was a frame off build three years ago with the front crossmember/suspension being replaced with squarebody parts. New a arm bushings (rubber) were pressed in. Cab mounts are red poly. I'm thinking either of those two are the culprit. It's louder when my fresh air vent is open. It squeeks on the small ripply road cracks but not on bigger bumps and I can't reproduce the squeek rocking the truck in the shop. The squeek will decrease and almost disappear on really hot days. Cold days it's almost constant unless on really smooth road.
What would be involved in replacing my cab mounts? Is it possible with all the front sheet metal on?