was the 88 a V6? Did you change your oil pressure sender?

 

you can just swap the gauge display. just take off the trim covering the cluster, unhook the speedo cable(its quite hairy back there so be careful), unhook the 3 electrical plugs (remember where they go.. doesnt matter if you forget where, they only go in one way, its just easier) unscrew the 3 or 5 self tapping screws that hold the cluster to the dash, and vuala! your new cluster goes right in. if you dont need any other cables, the installation is the opposite of removal. ive done this a few times with my truck, and while its not easy (that truck STILL bites me when i do that) i can do it quickly. good luck brotha, get some pics up here when you finish

 

Just buy a 30 dollar sunpro tach. The stock tach is HORRIBLE, It jumps all over the place. Just buy the 3 gauge pod from that one guy.

 

My tach gauge doesn't jump hardly at all. And, for some reason, it works. And I have a 22R and I did not use a jump wire. Weird eh?

Anyway, my gauge went in flawlessly (minus the SR5 sending unit I had to install).

And FORGET about buying that NEW oil gauge! The Toyota dealer over here priced it at $185!!! For that ONE gauge alone!

 

When i put an auto cluster into my truck i had to move a couple pins for it to display properly but i havent heard of anyone else with the same problem so idk what the deal is? but its all set up now and working, dont have a volt meter but i dont really care, and my tach works fine and never jumps.