1989 fc 15" wheels ????? or 16"

[V8 RX-7]

i have a 1989 fc with a rover v8 fitted for racing autograss ive only got 4 standard 16" wheels,5 stud can anyone tell me whether 5 stud from say a mazda 3 will fit, they dont have to be anything fancy its easier to get hold of 15" race tyres, or if anyone has a couple of 16" ones for sale pm treeuk@gmail.com cheers