Here is my advice, you will have a bussy day.
Look at the front axle king pin bolts do they both run the same dirrection have the nuts on the front or back especialy Dana/Spicer. These axles are notorious for requiring machine work in fact most medium duty axles need to be machined even if they dont show play . You wont be able to determine out of round or wear of a couple few thousandths unless you have a set of mahinist standards or bore guages. If both kingpin bolts face front or rear you have to bore and sleave this style axle when replacing the pins, except for replacing the axles nothing else can be done just a bad design.
ALSO......
New or old and worn drums?, front brakes out of adjustment?, did they center the drums and wheels?, worn wheel bearings and are they prpoerly loaded or tightened, if sealed units are they worn? was the truck allinged when you had the work done, did you have the tires re torqued afterwards especialy with new hubs? Is there good quality lube and not the cheap crap. are the tierods and pitman arm and steering box in good shape? check the spring perches, bolts, bushings, and springs themselves. Did your steer or drive axle shift? This check typicaly requires an alignment rack.
Were the steer tires replaced?, matching tread and even depth? are they good quality branded tires or the cheap off brand and age? off brands work OK for trailers and drives but you realy want a good quality steer. Also check the engine and transmission mounts for wear, check the the U jounts and carrier bearing for wear, check the drive shaft for dammage or on a rare occasion a thrown weight, then, run the rear axle springs, check everything preches, shackles, bolts, brakes, wheel bearings, wheels, tires check every thing. remember rear end issues can, do and will travel allong the chasis and drive shaft and raise hell with the front end.
All these can cause vibration and and shaking. keep in mind you are driving a truck and it will not drive smooth like a rolls royce there will always be a suttle harmonic shake betwene 40 and 50 mph as the chasis flexes especialy if you have leaf springs both front and rear and loaded light or empty. Its somthing you can ignore or aclimate to, if its rough thats bad. If you give the truck a good rundown you should be able to find the problem. If you have any questions feel free to call me at 585 414 7732 8 AM to 9 PM Eastern time.
Good luck.
Bob Wolf