I use an 8" drop with a 6x12 box trailer w/ 14' wheels. When the trailer is loaded up it sits perfect, when it's empty, the trailer squats a little. I wouldn't use anything less than an 8" drop.

 

I needed a 10" drop to tow my Floe 12' enclosed snowmobile trailer level. Here is a link for measuring the drop you need.
http://www.etrailer.com/faq/ballmount.asp

Dave

 

I use an 8" drop, too. Keeps my utility trailer and boat level. I had to add weld strips along the top of mine to keep it from moving around inside the receiver. I sepnt many hours searching for a cushioned draw bar with enough drop to level my trailers. No such luck.

 

sorry to get off topic but in respond to Rat55chevy, we sell a device called the silent hitch pin. Its made by LetsGoAero. Basically its a thick flat bar that slides inside the ballmount that has a hole in the middle of the barwhich is threaded. After youre-insert the ballmount into the hitch, the hitchpin that you insert has threads which screws into the bar inside of the ballmount. When you tighten the pin it sucks the ballmount to oneside and basically locks it into place. It also has a lock to keep it safe. Once you set it the first time you will need to re-tigthen it after you put a load on it.The load will loosen the ballmount.I have one on my Z-71 that pulls all of my toys and I've installed it once and re-tightened once and that was about 3 years ago. Pretty simple device and seems to work well. We sell a bunch of these to customers that use hitch baskets. Takes the play out...........Sorry to steal the post

http://www.letsgoaero.com/ProductDetail.asp?Pid=14here's a link.

 

Here's where I found my cushioned ball mount with a 10" drop. Works great. They have drops from 2-12".
http://www.towingproductsco.com/Cush...allMounts.html

 

Thanks TahoeDave, for the link. That's what I was looking for.

Thanks to you too, E. I can see where that woudl help horizontal or side to side play. Couldnt do anything for vertical or up down slop and thats why I welded a couple of rows along the top of my drawbar. Interesting product, though.