Hi guy's, Firstly I'm sorry for asking about the topic, I'm sure it has been done to death! I'm new to the site and had a look around but couldn't find anything directly related. I was wondering if anyone would be able to offer a little advice. You see I am in Australia and I am rebuilding a Ford V8 351 Cleveland engine, and One Oil getting the big push here is the Fully Imported USA Pennzoil GT Performance 20w50 aimed directly at the 60's to 80's older style American Styled V8's. I have wondered if this is considered a quality oil in the USA. One thing you might find interesting is our most commen oil is 20w 50's and becoming very popular are 15w 60's. There are allot of new engines getting around with 15w 40's but the norm for us is 20w 50. Over the last few years I have tried to gather as much info about this topic and one thing I have found is that there are still a large amount of high performance part makers and suppliers recommending the use of only high quality Mineral oils for the older style V8 engines. Even Crower are saying Kendal 20w 50 Mineral is the best they have found with there parts. Your time and any comments would be greatly appreciated. Francis.