The Best kit/Solenoid out this is the Hurts roll control.
They been making the solenoid since the begining.
Kit # 5671521 which is a complet kit for 05-09 mustang
No lines to remove etc kit is really nice.......
From October, 2011 until 4 weeks ago, SLP discontinue shipping their 07-09' line lock kits while they made some upgrades. I ordered mine from American Muscle on Ocober 25th and just received it on May 15th. Feel pretty confident that the new revised kit will be a quality addition. Never really heard of many GT500 folks having issues, but the Terminator kits had some major problems with premature solenoid failure.
Hurst Roll Control for 2 years. 2008 GT500. No problems.
Stay away from the Granatelli Tire Fryer. I purchased a set and the solenoids were trash. The retailer was nice enough to send another set, and they didn't work either. I called Granatelli, and they said that they used to have problems with that particular solenoid, but they fixed the problem. they sent another set, and they were bad also.
CFM is the easiest to install. The kit has two solenoids that mount at each caliper and comes with new stainless steel braided hoses. I can put that kit on in 20 minutes. Takes longer to bleed the lines than the install.