preference and questions about eaton/auburn posi unit

Well A-which one do you guys prefer and B-which units wil fit with an 84 stock rear, thanks

I have used both over the years and prefer Eaton as they have seemed (at least in my experiences) to last longer than the Auburn.Second reason I prefer the Eaton is it can be rebuilt when it wears out and starts the one wheel peel blues...the Auburn cannot be rebuilt.I also have had my Eatons take twice as long to wear out when properly maintained compared to the Auburns I've used.

which unit was it