Are the units all the same, if not, what about just the glass????

 

glass is the same but cosworth headlights have different fixings for the grill iirc. standard headlights can be modded to suit though

 

cut outs in a cossie onme to except the grill but standards can be moddied

 

If you get non cossie headlights you have to cut away a bit of plastic on the inside edge to fit the grill in.. Not a very hard job though!

 

some have extra webbing on the bit you cut out to help support them
the cossie ones have this webbing as well
some lights won't have this wupporting webbing, but it's not the end of the world, they only hold the grille into place and it's not as if it weighs in the millinos of tons

 

some have slightly different wiring and require an extra earth wire iirc