Driveshaft length tolerances +/-?

Well folks, feel free to say you told me so. I thought I had found a drive shaft that was the correct length according to the charts I found, so I installed it and BAM!! Three full inches too SHORT!!!! Don't ask how or why, but it was.D7194E5D-8705-4042-988B-5BBDCFEC3D8E.jpeg

Luckily I still had my old shaft, so I measured and had it cut by the driveline shop. I know, I know. You said to measure and I didn’t.