Will a 99 4wd grill fit without modifying onto my 99 2wd?
is there a difference?

thanks

 

There is a difference (at least in Tacomas, T100s, and regular Pickups). The trim is usually flipped. 4WD grilles are thicker on the top portion whereas 2WD grilles are thinner. Don't think they will fit unless the attachment clips match up. I don't think they are though, they are two different part numbers.