The HD X2 was what alot of people were wanting, a Holden that was fast. This car was fast, there is no doubting it, with a very usable 140 bhp the engine was lively compared to any Holden before it. The fact was this Holden was breathing down the neck of the powerful 225ci 145 bhp Valiants. The engine recieved some treatment other than just cam and carbs.
It used the following:
149 high compression head.
High lift camshaft.
2 carburettors from the 149ci
New cast aluminium inlet.
New cast iron exhaust header.
The X2 was showing a liking for drinking gasoline and too many mechanics were leaning the carburettors to save fuel and in the process were destroying valves.
The new heavier HD used the same track as the EH before it and with the engine being pushed 67 mm further forward did nothing for handling or braking! The early X2's had shocking brakes and suspension until midway thru 1965 when Holden released the new ball-joint front-end and twin-pot disc brake option. The X2 if bought as a Premier gave you bucket seats but the rest of the range still had the bench seat and along with no seatbelts left you hanging onto the window. This was why so many people of the era drove with there arm out of the window, not to look cool like they do these days!