banshee aftermarket shocks are basically the same eye to eye length as the suzuki LT250R. I had a banshee sitting in my garage with elka shocks on it and I personally measured them. I have laegers +2 arms on my LT250R and i have works shocks. they measure 14.75. banshee was 14.5 so by my math they would fit just fine. honda 250, 450, 400ex shocks all to long. like motoman said they are 16.5 and longer depending on a arm length they are for. Longer shocks can be used but it all depends on spring weights, valving and what not. shocks from other machines are sprung and valved for that specific machine like others have said. they are also built to their chassis.
Spend a little cash and just get some aftermarket shocks that fit your machine. There are a few good companies that offer shocks for the Lts still. I would buy elka stage 2 or 3 if i were to upgrade. thats just me.