The grille on the 760 is narrower than the 740. You'll need 740 grille brackets, a 740 grille, and probably the trim pieces (body color) that go underneath and around (L turned on it's side-shaped pieces...) the smaller 740 lights. You'll also need 740 side marker/turn signals.

Why whould you want to go backwards? The 760 lights are superior to the 740. The 760 also has foglights, the 740 has a rube goldberg setup underneath the bumper.

Note also that the hump in the middle of the hood on a 760 is narrower than the grille than on a 740. If you put a 740 grille and lights on a 760, the hump will not line up with the outer edges of the grille.

I went through a similar situation on my 90 740 when I put Euro 760 lights on it. See the reference webpage.
http://www.geocities.com/johndbinford/Starter.html