Eastwood ZDDP Oil Additive 4 oz.
Product Review (submitted on July 17, 2012):
When I found out when the motor oils today didn't have the required zinc as they did back in the day for older engines like the 283 V-8 in my 56 Chevy 210 2dr hdtp. I have notice a better running engine with the use of the ZDDP. I always have some on hand so when I do change oil, I can add it to the Mobil oil I use. I plan on using it in the 77 Corvette I just recently purchased. Very happy with the product.