For those of you who are interested in this swap and have the same truck here is a little informational so you can avoid one of the pitfalls I ran into. I recently installed a sport cluster in my 1991 v6 4x4 mighty max, got everything installed including the oil pressure sending unit and everything worked great, except the tach and that really sucked since it was the main reason for doing the swap so I hit the books, well the internet actually. From everything I found it looked as if the truck did not come pre-wired for the tach however after 4 trips to the wrecking yard and a day of confusion I found out what the problem was. It turns out the trucks, at least the 4x4 v6's and I'm pretty sure all v6's come pre wired for the tach (I cannot speak for the 4 cylinders). The only thing is some of them (like mine) are missing a key component that makes the tach work. Pictures of this device and the mounting location are attached. Now if you need this device the V6 montero has the exact same device in the same location as our truck and it is a direct fit and of course the max's with a sport cluster do as well. If you really get stuck in a bind and cannot find one I have a couple extra and I will mail one to you free of charge If you PM your address to me (keep in mind they came off of a used vehicle and are not new). I hope this helps someone out because I could've used the info when I went to install my cluster.