When I first started looking for Z Bars at local
Swap meets. Everyone said 55,56 and 57's were
the same and the different lengths were between
6 cylinder engines and V-8s. Boy were they wrong
The 55 with General Motors Part number 3724177
is shorter because the engine side ballstud bracket
is straight not offset towards the engine like the 1956
and 1957 bellcranks.



1955 Chevy Passenger car equalizer
 Short and stubby is about the only way to describe
the " 177" Z-bar.


Measurements
The main "pipe" is 5 1/16" end to end. The lower
rod tab is 2 1/4" from the center of the pipe to the
center of the rod hole. Upper rod hole is 3 3/4"
center to center.


Bushing Engine Side
The example I have has a bushing that reduces the
Hole size to around 5/8" to match up with the small
ball stud used in 1955.


Bushing Frame Side
There is the same size bushing on the frame side
end. The part # 3716811 bushing would need to
be installed in this New Old Stock part.


N.O.S.
This part has a small GM part number tag on it.
The small hole on the lower push rod tab is 5/16".