Suspension help

[ramo]

Greetings everyone,

I am the proud new owner of an 84 C-30 Sylverado 1ton 2-wd. I have owned the truck almost 6 months and have gutted the cab,replaced hvac system,shocks,gauges,dash,carpet,all knobs and buttons.
I recently had the oil ,tranny and diff gasgets replaced as well as all fluids changed along with brakes and axle seals.

My problem is that at speed when i hit a bump or hole the truck just goes left or right and at highway speed 55-65, the truck is a fight to keep straight because it drifts something terrible.
If anyone can shed some light on this problem i would greatly appreciate it as i am at a loss.

[Zane M]

Start with the simple by checking for play in the tie rods and ball joints.

[ramo]

seeing that the majority of everything under there is at least 30 yrs old, should i just replace it all (bushings,ball joints,seals)anyway and rule it all out in the process.

[Zane M]

It definitely would be a good idea.