They are not extensions but they are eccentric and adjustable. They are a little more expensive but they will do the trick. Keep in mind when its lifted that is one of the scarafices you make you change the steering geometry. But they are available so check Ebay and most parts houses will have them. Also low cost is not what you wany you only want to do this once in a great while lots of work.
89 2.5 TBI, 4" RC lift, 1" Booms, SYE, Adams Driveshafts front and rear, Ford 8.8 with 4:88s, BFG 33X12.50X15, and a ton of other stuff.
AF Jeep Club Tail Number 184