Hello Mark; When you say "First with 4 wheel discs in Landau" - LTD had same and they were released at the same time. For some reason I thought the LTD was first, and Landau shortly after, but everything I read says they were released together. So while not as "racing/glamorous" it would be more correct to say that "Ford were first with rear discs in the LTD/Landau range - as LTD's were the bulk of the sales. So the major leader with rear discs was our "lux Limo" :-) I had an LTD with those rear discs. I used it to tow a heavy boat; and had never experienced the difference that discs could make from drums on the back - but the boat on the back down a mountain pass........ HUGE difference. My LTD had a top loader manual from an XY GT and an F100 11 inch clutch. The park brake mechanism was the stupid part of the brakes. VERY complex and made a disc caliper (essentially simple) far more complex than it needed to be. It wouldn't hold the car - adjust it up and it drags. Stupid idea. Ignore that (never use it :-) ) and the rear brakes were brilliant - have no trouble with them........... Well; I say "No trouble" - they didn't work when I got the car, fronts locked up under hard braking;and everyone I spoke to said "Yeah, s*** system/doesn't work/why do you think Ford ONLY used it on LTD and not GT?????" Hmmmm. I ignored that (took it as "pub talk/we don't understand it = it's shit) and stripped the only part that was different to an XA........... the proportioning valve. Was a bit dirty. Cleaned it = BRILLIANT!!!!! And was for the rest of the time I had the car. Ford seemed to have a lot of trouble with the "intgrate park brake into rear discs" judging by the amount of people right through late XF era Falcons that fried the rear pads from "park brake stuck on". They finally gave up the stubbornness and reverted to the idea that Euros use where they have a small "mini drum" in the disc hub with separate pads for the park brake. Finally a system that worked. The boat in the pic below was 25 feet and timber - very heavy. Should have had brakes on the trailer, but didn't. I needed those rear discs more than most - I needed all the help I could get!!!!!!! I only moved it when I had to......................