You can still run the bumper but its a little to norrow. Looks weird and messes up the part of the fender that bolts to the bumper..
the fenders are different shape and use different bumper caps the 2wd caps have more of a 90 degree angle to them and the 4x4 caps are more rounded so they will not work right together. also the 4x4 bumper is a little taller and possibly a bit longer then the 2wd one so if u use the fenders gotta use the bumper + caps to go with it unless u wanna customize otherwise they all just bolt right up. if u dont believe me i can take pictures of them all as comparisons i know this because i have tried to interchange these pieces. heres an idea on how the 4x4 fenders look on a 2wd my toyota pickup pictures by havok8888 - Photobucket
I had the same issue with my 88 toy so I modified a 1990 4Runner bumper on it and it looks sweet....!