I got two with the my car and one measures 6 inches from the pivot point to the clutch fork pushrod and the other measures 7 1/8 th.
which is correct for my 71 chevelle?
Thanks all!

It makes sense that the longer one will provide better mechanical leverage but I still need to know if it can be used.
Thanks!

Are they both GM? Unfortunately I dont know the length of mine.

Test fit each fork in your bell housing with TO bearing installed and then mount the bell housing to your transmission and see which one fits. The one that fits should contact the TO bearing at 12 and 6 oclock and clear the trans shaft.

Thanks for the replies.
Wayne-They both contact at 12 and 6 and are identiacal except that the one comes out of the bellhousing an inch farther than the shorter one.
In the hunt for a good restoration it would be cool to know which one is correct.
Anyone got a tape measure ?
Thanks all.

Had a brand new original GM fork for my 71 sitting here for months. Just installed it 2 weeks ago. Have no idea of length now. 2 weeks too late Johnny
Wait, it had to be days too late I see this thread is from march 15
Does either one have this part number on it # 5014090. That suppose to be 64-72 chevelle

It was hard to get clean measurement points, but from under the car I laid a tape measure across the flat around the fork dimple for the clutch rod and angled the tape measure down slightly and got 3 3/8 inches from the end of the clutch fork to the nearest bell housing rib. Bad explanation, but hope this helps.

The shorter one is correct for your year car, the longer one will give you problems. You may want to call us on Wednesday to confirm (make sure you have your fork in your hands when you call).

Thanks for that heads up Jeff!
Do you by any chance know why the longer one creates an issue?
Thanks,Johnny.

The shorter fork is to the right fork your car. GM designed the entire clutch linkage system to work properly with a specific length fork (a geometry issue). As soon as you start changing components (longer clutch fork) you start changing geometry which leads to problems.
Specifically, the problem with using the longer fork in your year car is that you will need to push your clutch pedal in farther to release the clutch - this will cause you to have to adjust most of the free play out of the pedal so that you can get enough stroke to release the clutch - even with this extra stroke you may still need to depress the pedal farther than normal (into the floorboard) and with all this you still may not be able to release the clutch even still.
People have used the longer clutch fork (when a shorter fork was called for) and have made it work OK but there is no good reason that I can think of to use it. The correct solution is to use the proper fork because it simply works correctly and there is no benefit (only potential problems) when using the longer fork. The longer fork is for 1973+ model years.
I know all this because a while back I mistakenly used the longer fork on my 1970 Camaro and I experienced the problems described above. After researching it, I found out the shorter fork was correct for my application, I switched forks and eliminated the problems.
The longer fork is marketed as a "Heavy Duty" unit that will work for the early year (pre-73 applications) as well as the 1973+ applications. Personally, I do not buy into the "heavy duty" thing.