#340278 73-78 Truck and Car
General Motors Part # 340278 Clutch Release Fork
The GM "278" Clutch Release Fork. I own two
used forks with 340278 stamped on them. GM
dealerships list this Fork as being superseded
by the 140066235 fork. The 1986 Parts history
catalog simply says "340278 use 140066235".
Many aftermarket vendors list both part numbers
on their boxes.
From bearing end tip to center of push rod pocket
measures 10 5/8". The N.O.S. "235" Fork that I
have is 1/8" shorter, which is the only difference
I can find between it and this fork. The "278" and
"235" forks are some times referred to as GM's
Heavy Duty release levers because of their beefy
The two examples I own have the part number
stamped on the arm .
This example has a clutch return spring bracket
bolted to the bottom rail. Also notice the push
rod pocket on the right end is offset toward the
This Fork has a curve that would make it closer to
This is a close up of the clutch return spring
This is a side by side picture comparing a "278"
(bottom), with a "632" fork (top)
This is a Picture comparing the used "278" to a
Dorman 340278/14066235 fork. (very close)
0.795 FORK, clutch release
73-74 All (454) (Chevy)
73-75 All (350) (Chevy)
75 Nova (262)
73-75 All( 6cyl.) (Chevy)
73-75 All (6 cyl.) (Chevy)
66-74 irrig.Eng. (Olds)
73-74 L6 Opt. L34,M11,M15 (Olds)
73 All A Opt. M15,M20 (Olds)
75 All X,A 260 Eng. (Olds)
75 L6 Eng. (Olds)
75 ALL 250 M.T. (Pontiac)
73-77 A (Buick Parts Books)
73-77 Chevelle (Chevy Parts Books)
6262800 use 340278
330809 to 340278
340278 use 14066235
Factory correct applications are your responsibility. GM made part and part # changes with no rhyme but a reason (no production interruptions at any cost).
Application charts are for replacement parts that were available at the time of parts book printing.
My observations come from the parts I have in my collection or other reliable sources your parts may differ.
If Factory correctness is your goal, do more research, join car clubs,
forums and buy an assembly manual if one is available for your Project Car (you wont be sorry).
This is a fun and interesting part of the hobby!