Squeaky sound in old FJ62 Toyota truck with Leaf Springs and new Shocks, what could it be?

Just curious for any mechanics,
I have a pretty stiff, tired leaf-spring factory suspension setup which has 240k Miles, I replaced all 4 suspension/shocks with new cheap ones, prior to that it was not really drivable it shook around and then bounced a whole bunch afterwards.

(It was used as a Snowplow for 5 years or so, mostly highway miles besides that not much city driving.)

So anyway when Im going slow down the uneven pavement or alley roads, I hear a squeaky sound coming from the underbody that does not seem to be steering related, like when the vehicle shakes side to side there's a slight sound. Its new and I just noticed it today. Its been mostly parked since 2015, Im trying to burn through the tank of gas before it goes stale, Lol.

Since its a Toyota I think its like "If its not broke, don't fix it?" am I rite? Should I ignore this and see if it gets worse? I don't know what it could be. I also have new power steering pump because the old ones bearings were worn out from the plow... but yeah I just don't like sketchy squeaky sounds coming from my undercarriage. What else could be worn out from plowing?

Not sure what to check, don't own any tools. and its not serious enough to bug a shop about checking yet. So just ignore it or what could it be.

I just had the underbody greased up with u-joint grease and other serviceable points of lube, along with oil change and coolant/Tstat work. They checked the wheel bearings as well and everything else when it was in the shop and said it was good but a bit tired. (Worn) adjustable steering components.

Any Mechanics around?
BTW I love my old truck so much, Just thinking of the current economy situation with the interest rates, cost of vehicles, both new and used, and lack of good quality second hand Toyotas, I have to keep this running, and prepared for an end of society situation where I drive off into the sunset or onto a UFO.