getting pissed off!

Well im asking how to fix the gauge on a 64, with pics not a later unit. there is a differnce. and i cannot find anything except the picture of the back of the cluster, the site someone sticky is vauge and dos not tell me, hence why none of these work. i did read it i got nothing except i know it is the voltage limiter, so how do u modify the 64 valaint gauge inside? so that i can get it to work again with pics? has anyone done this and been succsessfull ???