My passenger side door on my 75 will not unlock... i have the door panel off on the inside and the lock cylinder out no matter what i do the lever to unlock won't move all the way so it will unlock need some help here assap guys

You might try having someone press in on the door from the outside while you try to move the lock mechanism. Might help, might not, but it's worth a shot. Lemme look at the lock schematics for a minute, and see if I can come up with something better...

Its a lovely thing when this happens(been there done that). The good thing is you have the door panel off and the locking mechanism. At the time mine did that the door way locked, closed, panel was still on and the lock securly in place. I will not go into detail but I did get it unlocked (use you imagination on this one not pretty). I suggest if you have the locking mechanism already off try to work it. But after working with both of mine I suggest (although expensive) replacing the mechanism with a new one this is what I did. If you amage to get it to work I can say through experiance it will fail again, and the taking of the door panels each time is too much hassle. After I replace both of mine no problems. The trouble with trying to reuse parts is not worth the trouble. Its up to you and you can get great replacement parts from any of the top suppliers of parts. Hope this helps but like I said itss worth it in my opition.

Make sure the handle outside is back up...sometimes the spring won't return the "squeeze handle" all the way back to 'home'... this might cause the lock lever to go all the way up....  just a thought...

 Good luck, Dante. Wish I could offer some help. Looking at the other post, I realize how lucky I was. I went to unlock the drivers door somewhere..no problem. The problem came when I went to open the door and nothing happened. the door would lock and unlock fine, just wouldn't open by the handle, inside or out. After a couple of body shops tried unsuccesfully to open it with various instruments, prying the panel away from the dsoor as far as possible,  yanking, pulling and prying on everything they could find, I gave up and went to play poker. After about the third stop on the way, climbing over the console, I finally just pulled the handle inside, slammed my shoulder into the door,and.......it pop open and has been working fine every since. (over a year ago). I wish you the same luck.

Well guys I got it to open finally. Using Adam's Apple's advice. I placed some pretty firm pressure on the outside door panel and then pushed hard on the inside lever to disengauge the lock and pulled the handle all in one swift motion and got her to open up, but I still can not get the mechanism to stay unlocked...  This was the first time trying to lock it the other day now I think I know why the previous owner left her wide open

Glad you got it open without having to resort to a chainsaw!
It may just need one of the rods/linkage adjusted to work properly....or maybe even a little lubrication!

I suggest you remove the mechanism and soak it in either carburator cleaner or paint thinner.  After it has soaked for a while, give it a day or so and then blow it out.  Sounds to me like it has filled up with crud over the years.

I'm guessing you do not have power locks so all I can do is feel your pain.I can't lock my Vette because the drivers door with stay locked until I lock and unlock my switch real fast and it finally unlocks.I've had my door panel off to fix a faulty power window motor and I greased it up and for a little time it seemed to work fine.Everytime I have to take it in for something I tell them do not lock to doors but they always do.

Woohoo my door lock is working better then ever I cleaned it really well with a can of carb cleaner let it dry over night then shot all the joints with some PB Blaster.. and it works awesome... I am about to do the same things to the other side...