Don't know much about the KREFT re-valve kit but I did have my suspension on my '15 300xcw revalved by KREFT. I feel they were very good. This is when he was still in Austin. Now that he is in Oregon I went a different route. I met Alan Cotton who is 812 Suspension in Round Rock at a TORCS race earlier this season. I was very impressed with him. I decided to let him refresh the suspension on my '15 since it was time and I was also having an issue with harshness at times. Couldn't have been happier when I got them back. I also had him set up my suspension on my '19 300XCW. I went with the Dal Soggio Spheres. Everything turned out great. I really recommend giving Alan a call at 812.
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Brian Sandifer #741
2019 300XC-W TPI
2015 300XC-W
TORCS 40+C