The big news in 1955 is the introduction of the FLH super sport model.
There are also some significant engine design changes.
larger engine cases with timken main bearings, o-ring intakes, crowned pinion shaft.
other changes include a  new tank emblem design. and a oval shaped taillight painted to match fender.

1955 brochure
1955 brochure

 

 

 

Here are some great sources for detailed information about Harley Davidson’s 1955 Panhead

How to restore your Harley-Davidson by Bruce Palmer 111

Riding vintage website

the Jocky Journal web forum

hydra-glide.com The panhead and flathead site

The Harley Davidson Panhead service manual 48-57 rigid

1955 models

modelengine typeactual displacementcompressionoptionsoptions
FL sport solo74 c.i.high compression73.66 c.i.7.25:1
FLF sport solo footshift74 c.i.high compression73.66 c.i.7.25:1F=foot shift
FLE sport solo traffic combination74 c.i.high compression73.66 c.i.7.25:1E=traffic comb.
FLEF sport solo traffic combination foot shift74 c.i.high compression73.66 c.i.7.25:1F=foot shiftE=traffic comb.
FLH super sport solo74 c.i.high compression73.66 c.i.8.0:1
FLHF super sport solo foot shift74 c.i.high compression73.66 c.i.8.0:1F=footshift

NOTE: the ” F denoting foot shift will not be stamped in serial number.

1955 models available colors

paintstripesspeedometer
blackblack outside white numbers grey center red indicator
pepper red
atomic blue
aztek brown
anniversary yellow
police white
police silver
hollywood green

black

1948 panhead black paint color

pepper red

atomic blue

aztek brown

anniversary yellow

police white

1948 panhead police white paint color

police silver

1948 panhead police silver paint color

hollywood green