do you need it for a stock car like my 95 Z28?

i changed the rear-end gear oil last summer with Lucas 75/90, and only put about 100 miles on it since.

since then i have found out there is a GM additive for the rear-end, and i am wondering, should i add it before i do any harm to my ride?

thanks.

some say yes some say no. i say its only 8 bucks or so and HIGHLY recommended by many. do it, you will feel better knowing you did.

I second that. It was put in there in the first place for a reason.