I know it's been a while (1-year+) but today I replaced the Silla all aluminum radiator due to it leaking near the driver's side tank. I replaced it with an ACDelco radiator (P/N 21653) for a 2500HD truck. It's 34" wide x 18-1/2" tall with a 1-1/8" core. Now the engine gets up to temp and stays there. I am sure it may take a little longer to get up to temp but it's nice having heat in the cold weather. It also has provisions for tranny and oil coolers but I am not using either as of now. I may in the future. Hope this can help some people up in the colder climates...