Hello Folks, I was checking out the oil aisle at Walmart , like i usually do, and saw this CastrolGTX Classic next to the regular GTX both in 20-50. When reading further, it states its formulated special for flat tappet engines that need added zinc. Its labeled as "High Zinc and phosphorous" . According to the data sheet on their website it has 1400 ppm zinc... Hey thats cool! At $5 bucks a qt. I picked up six quarts, 3 for the ural, and 3 for my Eldorado. Its nice to see they are making products for our vintage iron.
From the bottle label.....
"Castrol GTX Classic is a high performance formula for push-rod, flat tappet engines and performance cam applications. Specially formulated for classic/collector cars, muscle cars, hot rods, and race cars. Learn more at www.castrol.com
● Specialized additives containing high Zinc and Phosphorus for extreme wear protection
● Formulated to maintain tough and thick oil film even under severe conditions
● Minimal foaming and high resistance to thermal degradation
● Compatible with gasoline and alcohol based fuels
NOT RECOMMENDED FOR USE IN MODERN VEHICLES WITH CATALYTIC CONVERTERS
● Meets API SJ"