Will the grill for a 1997 Tacoma 4x4 fit a 1990 Toyota pickup 4x4?

 

Given enough time, tools, and money, the answer is yes. And patience. You'll need lots of that.
You're not giving us much to go on here. Is your grill all smashed up? Did you get some free parts? Someone bet you it couldn't be done? These are all important questions. Here's some more. Do you have a garage? Fabricating skills? A wife/girlfriend/boyfriend/significant other who won't grind you about how much time you're wasting cursing at your truck when you could be spending time with him/her?
Can you admit defeat and learn from your mistakes?
I'm not trying to discourage you. Perhaps you'll get lucky and it will be a straight up bolt-on swap. Not bloody likely, but there's always a chance. My gut says no.
Anyway, good luck. Give us a write up when you're done. Don't forget pictures.

 

I looked into doing this conversion a while back and found the tacoma grills are a little wider then the pickup grills, The tacoma headlights are farther apart and the tacoma grill bows out more and might interfere with the hood when closed.

 

i did a grill conversion. pm for pics

 

tuber bumper and grill