Schmidty Racing Suspensions
He can give you just about an extra 2" inches of travel and he's cheap. I had him do my stock rear shock and the suspension soaks it up like a champ.
However when you call him you need to tell him swing arm length, riding style, body weight and color you want the spring. The only thing I wasn't happy with is I think the spring he used was too light. I have mine adjusted all the way tight and it's still a tad too soft for my liking. Pretty sure he charged me $125 for the rebuild and an extra $75 to do the LT mod.
CORRECTION: Evan charged me an extra $50 (not $75) for the LT upgrade.
Back in the day a lot of racers did this trick but I've also heard the piston rod can end up bent. Knock on wood so far so good.
I've talked to Jake Balsiger owner of Six 5 Design about building a long travel linkage setup for the 250R and he plans to have some products for us out around mid summer. If you haven't heard of them it's because they are a new company and are working on getting there product line completed. You can check them out on there facebook page Six 5 Design - Product/Service - Chardon, OH | Facebook and if your interested the best thing to do is let them know what kind of products you would like to see.
SRS like deadly posted does great work, he redid a works shock i sent him falling apart missing clickers no oil etc, a basket case. i got back a beautiful anodized shock valved perfect for us +6 swinger etc amazing riding shock. im about to send him 4 more shocks to setup for us.
but you can swap the shim stack upside down in most shocks and get another 1inch of shock travel which is more wheel travel at the end of swingarm
you dont have to run LT front and rear, they work independantly from each other but once you try one you'll want the other to be the same. it rides so nice when the suspension just soaks up the bumps like butter.
I called Shmidty Racing and Evan seems real knowledgeable on what works for these 250rs. Unlike most people he gave me some options and went into detail what he can do with my stock rear. IMO of the suspension companies that i have spoken to Hes getting my buisness
Some guy on exriders just did a build with a long travel rear end on a prp frame. I think he used aftermarket trx450r linkage and moved the rear shock mount on the frame. Ill try to post a link to his build. Here it is, ATV Riders Forum - 2012 XC/Harescramble 250R Build , i think this dude really knows his 250r's.