Doing some maintenance on my 91 Ranger 5 speed. Can anyone tell me what the black seal is called and where I can get another one. Or just anything that I can use to replace it? This area experiences a lot of heat as you can tell. It feels like it’s some kind of foam material.

 

That stuff is nothing more than a piece of deadning material. Easily replaced with a piece of Dynamat.
A piece 12" x 24" runs about 18 bucks on Amazon. But any type of sound/heat mat will do.
Grumpaw