Due to its age, Whirlpool says they cannot be sure of the capacity. Models made during that time where between 2.7-3.2 cu ft. I believe it's a 3.2 cu ft model.
Here are three similar Kenmore top-load models (made by Whirlpool for Sears) with larger capacities: sears.com/kenmore-top-load-washer-w-deep-fill-option-8212-3.5/p-02620232000P?rrec=truesears.com/kenmore-2620362-3.8-cu-ft-top-load-washer/p-A015131820?sellerId=SEARSsears.com/kenmore-22352-4.2-cu-ft-top-load-washer/p-02622352000P?sellerId=SEARS
These three Kenmore models have a deep fill option that can be used to add extra water. Deep Fill is not available on Normal cycles due to government regulations. NOTE: Due to government relations all washers on the market today are High Efficiency washers.
All top-load washers: sears.com/appliances-washers-top-load-washers/b-1101278?searsTab=true
Hope this helps!