Even though we share many things with the Trooper, i am guessing that the stock VX springs are shorter than the stock Trooper springs and that is why there is more lift with after market springs. I am sure that the Amigo/Rodeo stock springs are also a different size and who knows how much lift you will get with the 913 springs. I don't know of anyone with a VX with the 913, but the site on this page:

http://www.independent4x.com/item.html?PRID=1027874

seems to show that the 913 might give you less lift or none at all. If you check out the listings of coils to choose from on the bottom of the page it also gives the amount of lift of each coil. The 913's seem to give about an inch less than the 912's. Check it out! I too love my OME springs, much better than stock.

(Thanks Paul! Got it to work!)