Which LSD will fit as replacement for long neck open diff

[cam1602]

I’ve search and found some interesting answers but not complete yet. I understand that the 320I style LSD diff will fit with some modification due to the Short neck Vs Long neck style diffs. Will the newer style diffs fit? Which LSDs have more than 25% locking? What are the other options? I can cut and weld if necessary, just need something close with with high locking (50% or more range) and low gears (4:11 range). Oh and need to be able to find it at a salavage yard to save $.

TIA

(edit to correct type-o)

[TobyB]

just need something close with with high locking (50% or more range) and low gears (4:11 range). Oh and need to be able to find it at a salavage year to save $.

That won't happen. Unless you swap to a solid rear axle and use a ford 9".

Seriously, a 4.11 r&p seems to go for $150+,

a LSD (untested) is up to $250,

and then you need a new subframe and probably trailing arms, driveshaft and cv's,

Then rebuild the LSD to tighten it (500- 1500),

and put it all together.

Easy.

t

[Mike Self]

Easy way...convert to a shortneck rear subframe and driveshaft, get a 320i diff plus the spacers and be happy with a 3.90 final drive.

Hard way...search junkyards for a longneck LSD from an NK TISA or TI...not gonna be easy to find 'cause few were sold in the US. You just might check with Carl Nelson at La Jolla Independent...there's just no telling what he may have stashed in a dark corner somewhere.

cheers and good luck

mike

[kbmb02]

Check with Ireland Engineering if you want to keep it simple and change only the long neck . . . I believe they've got one with 4.1 gears (though it may be a welded).

If you go with the short neck update, I've got a 4.1 gear set and the parts to build an LSD diff (definitely not cheap if you're going for 50% lockup).

[BarryA]

gears from an early 1600 long neck diff with the LSD carrier from an early (77 - 79) E21 320iS. Will require the services of a knowledgable and skilled BMW tech with experience rebuilding diffs, and will probably also require some fabrication and machining.

I want to retain the original long neck diff / suspension in my 69, but want a 3.64 LSD - have done a bunch of research, and the above seems to be the only practical way to get it.