While the paint scheme and the tank badge did come up with new improvements it seemed that the 1963 Harley Davidson DUO GLIDE FLH failed to impress the wider audience as no other considerable changes were made. When taken into consideration the 1961 models, it seemed that Harley did not fail to impress. The age-old 'waste spark' ignition in those said models was altered in trade for a much more modern concept. This system was complicated coming with the two sets of points and coils.

The said change was tried on but only lasted till the year 1964. Following this year the old concept of the 'waste spark' again came into existence. Many 1963 Harley Davidson DUO GLIDE FLH motorcycles were fitted with saddlebags along with the inclusion of Buddy seat which is made for two passengers. This is in addition to the windshield all of which are considered to be mandatory for the perfectly shaped motorcycle which is mainly made for long rides.

When the 1963 Harley Davidson DUO GLIDE FLH is taken into account, it can be seen that it is a much-improved bike design. This particular design has huge hopes when it comes to carrying the company's image for the next 17 years. The Panhead engine with the hydraulic valve came into existence in the year of 1978. The telescopic front forks that are the signature design for the bike and by which the bike got its name came into the market the very next year.

The 1963 Harley Davidson DUO GLIDE FLH has the 74 cubic inches OHV v-twin engine which is powered with a 55 hp and is fed by the Schebler carburetor. Apart from this, the motorcycle comes with a bucket saddle and a four-speed hand shifted gearbox. The other features which made the bike stand out were the telescopic Hydra Glide front forks and the hardtail rear end. Considering the breaking aspects there was the hand-operated drum brake for the front wheel and a foot operated brake for the rear wheel.

The highly noted feature was the aluminum cylinder heads, which also has the bronze valve, inserts along with the steel guides in them. The cylinder heads in this case also came with the steel inserts for the cylinder bolts and plugs. This was accompanied with the said push rod type hydraulic lifters in the case of the valve train. The aluminum heads here were noted to dissipate heat much faster. When taken into consideration the rocker arms and the cylinder heads, it was seen that these parts were thoroughly modified when in comparison with the 'Knucklehead' engine.

With the added new camshaft along with the exhaust ports with a new intake manifold, the motorcycle seemed to give an added 5hp. The placement of a larger oil pump increased the oil flow by around 25 percent to the valves in the case where it was needed. During the time of Harley's 50th anniversary, the 1953 bikes were all seen to have featured a big gold badge indicating this occasion. Three years later the Panhead motor also got high lift cams along with a flow-through air cleaner which combined to give an approximate 12 percent increase in power.