I have an 86 4x4 single cab that i wheel but i came to have a 91 2 wheel extended cab as well. I was wondering what parts will fit from my 91 to go on my 86m

 

Different generation models.

:wabbit2:

 

That's a bit too broad of a question to be answered really. Some will, some won't. It depends on any number of determining factors. Which you have not provided. IOW, you'll need to be more specific as to which parts you're wondering about. If by wondering you mean which parts from the 91 would be considered as upgrades for your 86? Very few, if any. In general, 2WDs are not built as tough as 4WDs. As such, most, if not all, of the parts on the 2WD would be inferior.