The clusters are identical in all years. Except that the big blocks have an 8 grand tach and the small blocks are 7 grand. They will bolt right up to all the existing wiring. But you will need an oil pressure sending unit( barrel design) to bolt in the back of the block for a small block and the front of the block for a big block. Take out the oil pressure sending unit for a light and replace it with the guage unit. Then you will need to run a wire from the tach to the negative side of the coil. Hopefully they will leave the tach wire on and all you will have to do is run it to the coil. Good luck and try not to peg the speedo.