my 28x9-15 MT ET drags fit my FC but only with serious rolling of the fenders, they are 11.8" wide at the sidewall ('section width')on an 8" wheel, they rub the inner fender ever so slightly as well as the control arm... but only on a very hard launch and it just scuffs it occasionally... I have a gnat's hair clearance on both sides normally, but the tire distorts on launch.
I assume FC ??? also assume MT ET streets ????? if so, yes they will probably fit, with rolling the fenders, on a 8" wheel with 25mm offset or 5.5" backspace... some models of jeep wheels are one cheap alternative. the ET streets measure width at the sidewall. if that's an ET drag or other brand/model of slick, IDK..... different brands/models of the same size tire can vary significantly.
more info might help us help you.