The Mk.2 electrical system can be fitted almost as easily as an original Mk.1 harness, and the upgraded fuse/relay panel fits the Mk.1 cradle.
I installed one on my '79 for a 16V swap, and the only thing I had to splice was the tail light harness, and the fuel gauge sending unit, you just remove the 3 terminals from the S2 '85+ transfer fuel pump connector, and then install them in the original connector.
Like Lego's...




