i got my springs over 2 years ago. i got the regular sas kit from here or whatever. im not sure what springs i have or if they even had the usa ones back then. if i do have the imports/usa they have worked excellent. my truck still sits level in the front and flexs great. over the last few months my springs have settled a ton, but ive also had them for over 2 years now. it doesnt bother me cause im liking how low my truck is in the front. either way buy what you want and get it from marlin.