You are most probably correct to assume that it has been changed, because as noted there are quite a few changes between the 77 and the 84. Some of the functions would work OK, some will be off, like the speedometer, some won't work, like the tach, or it won't have a tach. But it will fill the space correctly and I think that most of the electrical wiring would be OK.

__________________
Junqueyardjim
Christianity, if false, is of no importance, and if true, of infinite importance. The only thing it cannot be is moderately important. C.S. Lewis



1983 Mercedes W123 240D 4 Speed 285,000 on the road with a 617 turbo, beautiful butter yellow, license plate # 83 240D INDIANA

2003 Jaguar Type X, AWD. beautiful, good mileage,
Mom's car, but I won't let her drive it!