Would this load the arguments and return value for a function?

Question

Given code

void (*functionPtr)() = fun2;
    unsigned long long int *intPtr = (unsigned long long int *)functionPtr;
    intPtr = intPtr - 8;
    *intPtr = 0x00000000;
    intPtr = intPtr - 8;
    *intPtr = (unsigned long long int)08;

Would this successfully fill the argument of fun2 with 08 and the return address with Ox00000000?