1999 2wd ford ranger tire clearance

[crawfost]

Hey. I was wondering what is the biggest tires I can run stock with 2" wheel spacers?

 

[JohnnyO]

Don't use 2" wheel spacers. Ideally you want a 15x8 wheel with 3.75" backspace.
Biggest on stock rims would be a 235/75-15 or 30x9.50-15.
If you mean you're looking at something like a 255/40-20, those kind of tires and wheels are not my ball of wax.