skinnies

I was wondering would a 15x5” Wheels with a 3/5 half backspacing work on the front of a 1993 firebird without using spacers.

Depends on the brand/model of the wheels.

You also might want to clarify what "3/5" backspacing means.... I'm not familiar with that way of showing backspace. Or do you mean 3-1/2" ?