bp castrol makes a special xmsn fluid for allison trannys good for 50k for severe service and 100k for normal duty. no vii is needed according to their product lit. does any forum member here no whether it is acceptable to use transynd or a generic counterpart in a G M 4l60e that specs a dexron lll? I have put 94k miles on my astro in 3.5 yaers and think the ends would justify the means for my type of driving. much appreciation for the input!