no offense, i wouldnt sink the $ into widening & chroming the stockers, they'll be too heavy and for the price you could prob get a better set of after market ones or pick up the chrome SS @ a scrap yard. Check for some 05'ish Bonne SSEI or later Grand Prix 18s, the GPs are chrome 5 spoke style and nice, the bonne's have the same ri, put a matte finish
the 16x8s i have for my 255 50 16 (slicks) rub when i turn hard to make the trip down the return road @the thrack, so i wouldnt go too much wider than that.
check w. a tire shop, they should know how wide you can go w/o rubbing 4 sure