1982 Datsun ka24de build

[Jordan middleton]

I am starting to put together a build list for my 82 720 ka24de build and I’m asking the community for recommendations on a rear end 

[datzenmike]

The stock one is certainly strong enough. Look on the engine tag located under the right hood hinge riveted to the inner fender. Bottom right corner of tag will be the differential ratio. For an '82 2wd the most common is an HF38 which is Nissan speak for a 3.889 ratio. A KA will have no problem turning this though I suppose the KA is powerful enough to turn something lower like a 3.545 but why bother? The H-190 differentials were used in the Hardbody and Xterra KA up into the 2000s and may be being used to-day?

[]2eDeYe]

I run a 3:54 in my 620  with a 720 5-speed and a KA24DE and have no issues. It is a freeway eater. 🙂

[bottomwatcher]

Its the 82 transmission that will blow up on you. Plan on installing a c series trans.

[datzenmike]

Agree. If you get the engine get the trans that comes with it. You will need to modify the driveshaft for length. Hardbody 5 speeds are slightly shorter than the 720 so it might need lengthening. 240SX are definitely longer and will need shortening. If you have the 26" 'shorty' 5 speed, then both will need a longer driveshaft.

[]2eDeYe]

2 hours ago, bottomwatcher said:

Its the 82 transmission that will blow up on you. Plan on installing a c series trans.

 

 

Going on 10 years with an 83 trans and 83 diff.
Of course, my KA is stock. 😄

[Lockleaf]

I'm with redeye.  Trans failure is certainly a possibility, but I don't consider it a guarantee.  Much of that depends on driving habits, towing, etc.  I'm a pretty chill driver, I don't launch from lights or goose it hard out of turns or anything so stuff tends to last a good while for me.  It's shock load that typically breaks rear ends or transmissions.

[Crytek89]

On 2/14/2020 at 7:09 AM, datzenmike said:

Agree. If you get the engine get the trans that comes with it.

You'll also need to do a bit of cutting in the trans tunnel for the shifter as the location will be slightly different so just be aware of that.
As long as you're not clutch kicking the rear diff should hold up - I'd recommend checking your diff lube though.
If you plan to turbo the KA in the future I'd definitely recommend replacing the diff though - the KA can easily make 250-300hp boosted, but the rear diff will be in dangerous territory at that power level.