the speedometer cluster bolts in between 1979 and 1983, but the wire plugs changed a couple times so you'll have to do some splicing(get the plugs from the cluster that you're going to put in!). '79 used round plugs and i think '83 used square ones.

'79 sport 4x4 longbed <img src="/forums/images/graemlins/smile.gif" alt="" />
20/22R hybrid with EB's OS valves, 268c cam, offy intake, weber 32/36, thorley header, 5 speed swap, 34" LTBs, downey 3" springs, marlin hysteer, 4.88s and locked

'91 4x4 shortbed
22R-E, W56, the dd!