that's good to know. I've personally never bought those springs, but they are recommended alot here. I have heard quite a bit that the factory retainers were too small.... to error on the side of safety and buy new retainers. I generally have used the MP springs and had great luck. I used the eddy's for the 1st time on my 318. Hard to beat the price and the fitment was really impressive, if one is looking for a 340 spring replacement or mild build.