hey guys, i have a chance to p/u a 77 for parts. does any one know about compatibility between these two years. i have an 81 320i.

There are lots of differences, the front suspention is different and incompatable with an 81, the seats are different, the seat slider in in the floor between the seat and the door, the seat belts are bolted to the tranny tunnell and the seat belts themselves are different and won't work in an 81. the dash is different most of the switches are different the heater controls are different, mirrors are different, turn signals and blinkers are different (heck the 77 ones are wired differently than the 78s...) The in tank fuel pump is different. I'm sure there is more but I can't remember them all.

the 77 does how ever have the front vented disk brakes the 81 doesn't, and the 2.0L engine, and a lot of the other bits are the same, but the face lift in late 79 changed a lot about the cars.

whoa whoa whoa!!! seats from the older e21s don't bolt into the later ones? what year did this happen, just so i know for when i start looking for seats

The mounts for the seats that are part of the floor of the car are the same height on an early car. On a later model car the inboard mount (closest to the trans tunnel) is shorter.

On the early cars the seatbelt latch is bolted to the trans tunnel as mentioned earlier. On later model cars the seatbelt buckle is bolted to the seat. The inboard seat rail was made taller for this purpose on the late model cars.

I'm not sure what mods are needed to adapt seats from one mounting scheme to the other. This is also something to keep in mind if you want Recaros. The mounting rail setup is different between pre and post '79 cars.

- Steve

wow, i never caught that in my readings here or on bmwe21.net. thanks for the heads up

what's different about the dashes aside from the switches, etc.? Are the dash mounts the same?

whoa whoa whoa!!! seats from the older e21s don't bolt into the later ones? what year did this happen, just so i know for when i start looking for seats

You can swap them over, but you have to use the brackets from the later cars. That's what I did.

what's different about the dashes aside from the switches, etc.? Are the dash mounts the same?

I think people have used the early dashes in the later cars, but the vents and the shape are different.

You can swap them over, but you have to use the brackets from the later cars. That's what I did.

ok, thanks

the k-jet moved from an accessable upper engine location to an under the octopus of an intake manifold('80?). Lambda sond was added in '79 (meaning catalytic converters). Early cars weren't prewired for right side mirrors or foglights. From '79 MY on LSD was included in the sport package.

Would it be worth buying that 77 for the 4 wheel disc brakes alone? Front rotors are vented, while the rears are solid. Depending on the price of the 77, it would be worth it to me.

Are you saying it has rear brakes from a 323 installed? It didn't come with rear discs. Those usually go for $500-600 alone, so if you get a good eeal and its got a lot of good parts you'd be allright.

As for the seats I would not try to put the early ones in a late car. I tried to use one from a 2002 (which I believe is identicle to the rearly seats) and the stud where you want to attach the seatbelt catch is shorter on those ones so it doesn't work very well. You could easily go the other way by putting a big washer on the stud. The bottom brackets are different but interchangable.