Truck starting to shake....

My truck has begun to shake. Well, its really not a shake more like a slight vibration. I was on the expressway driving about 75, then when I got to my destination my truck was making a clunking sound on the passengers side of the engine when I came to my final stop. Let it sit for a couple hours, came out, and no more clunk, but now between 50-55 my truck shakes/vibrates a little. Any slower/faster, it doesnt happen. Help!

Thanks

1991 4.3 F.I. Carb

Where is the erg valve also?

Hello? Anyone out there? Someone has to have an idea. Please help.

dont know if this is what you mean, but the *EGR(exhaust gas recirculation) valve is on the backside of the cylinder head under the hood cowl.
if thats what you needed, i hope it helps! :)

Also, get your tires balanced and maybe an alignment.

Shocks? Have you ever seen a car driving down the road with one wheel bouncing like a basketball. This is often speed related and will change with tire pressure/temperature. If you haven't changed shocks in a few years, their due. If the vibration is break related it could be a warped rotor, remember to always use a torque wrench to do the final tightening on your wheels. This is the most common cause for warped rotors, it's used by some repair shops to make sure you come back for a break job.
Motor mounts, transmission mounts, exhaust system mounts, body mounts, remember anything that can wiggle will, and everything has a resonent frequency/speed.
Let us know what you find, so we can add it to the community consciousness.
see ya
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