992 carried a 16yd bucket while the 475 had a 12yd. So yes. It is closer to a 992 than a 988 which I think was a 10yd.
Don't have a copy of Cat Performance Handbook around here but the online spec's for the 988H show it as having a 10.0 cu/yd bucket. Back when this 475IIA was working in the quarry as a load and carry machine to the primary crusher it was most times running along with a 988 87A1964 machine. As I recall the 988 at that time was only a 6 yard machine, or a little more. Every letter increase for a Cat loaders seems to move up bucket size a bit. A quick look at Ritchie Auction site lists the bucket on a 988B as 7.1 yards and I know the 988 B were a step up from the 87A models. Of course if you start putting coal buckets on them all bets are off!
Yes, large loader sizes have increased so much since the models came out that I can't keep track of them.
Kind of like after the L model dozers came out, they're gonna have to resize them and add another model in there.
I think that Michigan 475 had a pretty good reputation back then, I guess Cat just slowly overtook their market share with equal or better loaders over the years, or more than likely just better support.