I know that the mechanism on the 75 and 76 are completely different. Can the late models fit an early door without modifications?

No

Thanks

The mechanism changed either very very early in the 73 model year, or in the 72-73 transition. The 75-76 winders are the same as the 73-74.

--DD

Then I must have some pre 73 doors on my 74.

Do you have reinforcing ribs in the door near the outer skin? If not, you have light weight early doors. You may have an early targa top to match the doors too.

There's a thread somewhere about how to put late regulators into an early door. I was considering it because mine work badly. Didn't seem too complicated, mostly just locating one new mounting point, assuming you could assemble all the parts.

If the windows don't fit well, then you might.

The early mechanism uses a cable in a sheath to move the window. The later one uses a scissor-type lift. The shape of the glass is different, the seals at the top are different, and lots of other details are different.

--DD

I think the thread - digging into hell - shows late installed into early doors

I have a bunch of window parts if you want to try.P.M. for details

You will either need to remove the front roller metal part from your glass or get new late style glass also.

Oh, you will also want new fuzzies for the front and rear tracks.
The early door aluminum track is shorter than the late. Not sure if you can get away with using the old one and the old end caps. Now I'm curious.


I know a guy.

Hmmm. I took over a '70 project. I wanted late style window/winders so I bought a set of late doors from a junk yard and had them painted along with the rest of the car. I never thought about trying to adapt the late windows to the early doors. The doors weren't that expensive and I probably saved my self a lot of work, but in the future if one had a set of good early doors and bad early winders, if all the parts were available would it be worthwhile to try to convert? Hmmm.

My 1970 had mismatched doors and someone had replaced the early passenger side door with a late one. I will just replace the drivers door when we repaint. I would like to have the same style doors on both sides.

914itis may be asking, can early doors be fitted to a late model 914. As far as I know, the answer is yes. I have retro fitted doors o n later cars because I wanted the lighter, early doors. The cable-type regulators are a little flimsy, but with maintenance, work just fine

No, the question was if I can remove the early mechanism and replace it with the late using an early door.

And the answer is yes. The downside being that you're going to need to switch over a lot of parts and also weld one mounting point on the early door to fit the later mechanism. So the question is not if you can, but if it's worth the work and expense. I was going to do the same thing, but once I understood everything that was involved decided to just rebuild my current early doors.

Mepstein was right, it's the "Diggin into Hell" thread, here the photo of the welded in piece to mount the later mechanism in an early door (post number 568 in the thread):



Not that big a deal, the hard part is assembling all the other different parts. The original question was can it be done "without modification", and the answer is yes it can be done, but not without modification.

Ok, I swapped my late window regulators into my 70 doors this weekend.
Took about 3 hrs total.

You can see the diff in the viewing windows in the door. The late door has a larger area that the regulator bolts too.

Early Door


Late door


I made a cardboard template of the late regulator then traced the bolt pattern onto the early frame.

Drilled out the holes, then enlarged the crank winder hole to 1-1/8 inch.

Next made a template of the area I would need to weld into the early viewing hole.

Cut the bracket out and bent the lower edge on a brake 90deg to stiffen the part.



Next, welded the bracket onto the early door and bolted the regulator in.



You can see the new locations of the bolts needed for the transplant. (blue tape)



To finish the transplant you need
late glass
late vent window frame with fuzzies. Vent glass is all the same.
late fuzzy to put in the rear window slider.

Doors are the simple solution.

There was a style of door on the early 73 cars that had the later winders but without the side impact beams (best of both worlds)

I have a set in my shed waiting to go on a car

True, if bolting silver doors onto a red car is the look you want.
Ask Paul 914itis how simple it was. Remove old doors, bolt on new, adjust gaps, transfer your locks, somewhere along the way bodywork and paint and buff the doors. Sometimes not so easy matching 45 yr old paint.

Just saying that it is a not so difficult alternative. The conversion is about a 3 on a scale of ten. After having all the tools out and templates made, did the second door in 35 minutes. Obviously you need a welder.
I do agree that the older doors probably offer some level of improved side collision safety, but they are significantly heavier also.