You need to start in the center though - set the center section at 20-21" with seed hoppers about 2/3 + filled. These planters are shipped with the center section lift wheels in the top hole. It should probably be in the center (of three) hole in most field conditions. There are several recent threads describing this problem and how to change the axle bolts relatively easily.

Once you get the center section set at 20" THEN level the planter at the tow point/lower links. THEN measure the toolbar to ground on end rows 1 and 16/32 measured in line with the seed.

Planting corn the bean units are up in the air off the rear of the bar. IF you are having problems with the ends of a 1790 being higher than the center section when planting corn, I will bet you a cup of coffee that the problem is NOT a need for weights at the ends but is a matter of the center section being too heavy/too low. 

The planter will appear gull wing from either the center section too low OR the wings to high. The way to tell is with a tape measure!

 In corn planting configuration the last thing that planter needs is more weight.

The Deere suggestion of adding 1000 lb is almost surely for when you have the splitter units down in the 15" configuration only. Then in hard ground you may very well need to add weights to the ends of the bar in some conditions.

I am glad to hear that someone is at least paying attention to their toolbar. Best of Luck.

Jim at Dawn