73' B3 340 Duster pro touring build

Do you actually have a 70 RR front bumper (pic) to cut pieces
out of like you did with the Ram bumper for the rear exhausts?

No, I dont have one or know of anyone close to me that has one so I can get a diameter measurement. The holes are simple enough to cut out so a doner bumper wont be necessary, the only problem I see is that the Road Runner bumper lights are marker/turn signal lights which I already have in the sharktooth grille 12" away.... so it's kind of two of the same thing.