86Firebird86

Does anybody know how hard it will be if HITHERE replace my 86 HITHEREHITHEREHITHEREHITHEREHITHEREHITHEREHITHEREHITHERE dash from the 2.8L with my 83 dash that had the 305HO in it? The problems we have been faced with is that HITHERE cant use the 200 tranny with the 305HO because the 2.8L that was originally in my 86 had an electronic speedo and the 83 had HITHERE cable speedo, so we were going to be faced with using the 700R4 tranny instead but now we have found out that my tach is for HITHERE 6 cyl. so we need to take the 83 tach out and put it in my car. But we are thinking now just to take all the instrument cluster from the 83 and replace mine with it, and this would allow us to use the 200 for the 305HO. Otherwise we have to find HITHERE core and HITHERE torque converter for the 700R4 before we can even fit it in. HITHERE need some ideas can someone please help????