Sorry, I am going to trust Brewers decades of research and experience. You can even use ATF in an A833, just like your claim that its just fine to use synthetic.... of course they will work because they are lubrication, but you still should not use them as many more times than not the results and performance of GL4 mineral based is better. May I ask why you disagree with Brewer and literally any other old school 4 speed builder? At this point I wish I had not engaged, sounds like wisdom caught you and ran you right over.