I have a 4in. trailmaster lift used that I have installed and it came with what looks like new after market torison bars and I am don't know which bars may let the truck flex better any thoughts? I also would like to know if the only place to get a Aussie Locker is from www.offroadlockers.com?

I am guessing whoever might know the answer will need more info. You should specify what year of truck you have. Is it a mini, Tacoma, or 4Runner?

The truck is a '89 I dont know what brand torison bars but they don't look oem.

Aussie Lockers are only available from www.offroadlockers.com. We appreciate your interest in the Aussie Locker. All models are in stock for next day delivery.

use the stock bars the larger ones are too stiff, keep em' as spares
what size tires will you be running?