I recently had a question pop into my head and am wondering exactly which lift I have. I'm not sure if I have the XD 5.5" or 4.5". Does anyone know a good way to figure it out? The question popped into my head when I changed out one of the bolts in the upper control arm yesterday. I couldn't find written anywhere the size of the bolt that broke. As it turned out, the best fit to replace it was an M10 (17mm). A 7/16? bolt was a little small. I'm going to contact RE today to get more in depth info from them, but thought I'd post here to see if anyone knew. Oh, and I looked in the install instructions, but there wasn't nothing specifically listed for bolt sizes. I'm sure the bolts are the same for both, but it's still one of those nice to know things.