the gqs use a vacum advance in the dizzy, all the fuel injection stuff bolts up to a gq, so i cant see why the carby gear wont bolt up to a skyline. try looking on some of the 4wd forums you should be able to find a carby manifold fairly easilly, ive threw a couple out over the years.
try http://www.outerlimits4x4.com/index.php