I have a 1999 ford ranger 4.0 v6 4x4 OHV and when I put it into gear it makes the bottom of the engine all the way to the transmission/transfer case and even the driveshaft to vibrate a lot but when I have it in idle it’s not shaking a lot. I had recently done a custom exhaust to it from where the flanges of the outer pipe meet and the cats to a side exit for the truck but after a couple days it started shaking the car violently so I removed the exhuast making it straight pipe and replaced the transmission mount thinking that was the problem but it still makes it shake the whole car. And while driving the more load I put on it the harder it shakes and it smells like burnt chicken after driving it near the transfer case.What could the problem be if y’all don’t mind helping me out?

things I have changed related to this situation:
Transmission mount
straight piped from the ends of the cats

 

Try proof-reading for clearer posts.
Any codes or "check engine" light?
Idling in N (neutral) gives you no shaking?
Did you check the other engine mounts?
How many miles are on your 1999?
What kind of shape is your transmission in? What's the ATF's level and condition?
Torque Converters age, can fail and shudder.

What prompted the custom exhaust? Was the original damaged? Did the driveshaft take a hit too?