GVWR tells the capability of a given car. Curb weight is the car weight . Payload = GVWR - Curb weight.
Your question should be answered by comparing the curb weighs of Y SR and Y LR, which is about 500 pounds. The difference should be the weight of the extra battery, the extra front motor, the extra stuffs to support the front motor.
The Y SR payload = 5222 - 3920 = 1302.
Unfortunately, the Y LR payload is smaller = 5302 - 4475 = 827, which is quite smaller than Y SR.
In other words, Y SR can carry much more load than Y LR, which is again about 500 pounds extra load.
By the way, I compared the above Y SR payload number with all other Tesla cars in production.
Y SR is the largest payload among all Tesla cars currently in production! The next closest one is X, which is the biggest Tesla.
In this sense, Tesla Y SR is a truly unique car. If you have Y SR, please enjoy this unique capability of Y SR, especially during this summer season.