You can also go to a truck dealer or repair shop (Kenworth, Mack etc.) they will be able to custom make one for you, with the pigtail as well. You can also buy battery positive terminals that are solder on. You will need a propane torch with a pencil flame tip, one positive solder type battery clamp, the correct length of battery cable, a length of 8ga wire for the fuse box connection and the necessary copper ends to attach the positive ends to the starter, and fuse box. Get a couple of appropriate sized shrink tubing, some rosin core solder and some electrical tape.
If you are going to make your own I have found the easiest way is to melt the solder into the battery cable clamp and then insert the battery and fuse box wires into the clamp(after you have bared the appropriate amount of wire of course
). Keep the torch on the clamp as you slowly insert the two wires. The solder will flow into the wires as you push it in. Same for the other ends. Oh yeah, make sure you put the shrink tubing on the cable before you solder the last connections on; often they won't go on after.