How do i change egr valve on 1983 5.0 - 1995 Ford F350

Other than testing the EGR valve, not many options. You really need a 4 gas analyzer to know what is coming out of the tailpipe. Otherwise you won't know if repairs have helped the problem.
When you say EGR numbers I'm not sure what you mean. Most of the time the test is for CO and HC gases, along with oxygen and Nox also in some areas. The EGR valve allows some exhaust gas to be recycled thru the engine and reburned. CO or HC could be high if the EGR system is not working.

4 cylinder model the EGR valve is located between 2 & 3 cylinder on intake manifold and between Carb and valve cover it has a diaphragm cover about 3 inches round and one vacuum hose 2 bolts holds it to the intake. V-6 models EGR valve is located on drivers side of engine just behind carb and about the same size and roundness and one hose two bolts.

this could be a fuel pressure problem or volume problem.if its to low and you push on the gas pedal you are opening the injectors longer to allow more gas to flow.it could also be a stuck open egr valve causing a vacuum leak stalling the car at idle.the popping sound you hear sounds like either one of these,lean running condition.

Your going to need a professional that can
figure out how to restore your very old vehicle
to OEM Specs,so you can pass inspection

Do you have an OBD 1 code reader Iwould look at the EGR valve first take if off and look in side the two passages on the intake manifold see if they clogged with carbon. Then take the EGR valve hold it upside down and spray some WD40 on the pentile if it leaks through the EGR it no good . The other thing would be the catyiltic convertor is blocked with it running at idle see what you are getting for exhust flow from the tailpipe. I also now of an after market place that you could get any part for this vehicle you need you need for this vehicle you see i have an 85 ranger

Find the EGR valve on the intake and locate the vacuum hose that is connected to it. Start the engine cold and as it warms up, pull the hose off and if it idles and drives fine, the EGR valve is bad and needs to be replaced. Please rate me on this answer.

Replace the EGR valve.

Check the firewall for a ballast resister. It's a little porcelain thing with either one blade connected wire or two on each side. Held to the firewall with one bolt in the center. Change that, and keep a spare on hand.

this problem is caused by carbon holding the EGR (exhaust gas recirculation) valve open, it is a very comon complaint, fixed 100's for the issue at my dealer. You can buy a EGR valve carbon trap from the dealer to stop the problem.

the jets on the carb may need to be tuned,also check the metering rods,you might be getting to much fuel not enough air,