742 case to 489

[74delta]

I have a 65 300 and locally found a rebuilt 489 case with 323 gears and sure grip. What would be entailed to swap that in instead of my 742 open case? Is the yoke the same or length difference?

 

[gyknot]

Only difference might be the U-joint width. They used a large (wider) and small (narrower) joint. Just measure the width of your current yoke and make sure its the same as the replacement yoke. The depth is the same.
If the width is different, you will need to make sure the spline count is the same if you decide to swap yokes. If I remember right, there is an earlier course spline and later fine spline but I do not know when the change was made. If I don't remember right, it will be pointed out here.

 

[57fury440]

There is a universal joint that is made to mate the two different sizes together. So if yours is the smaller size and the new one is the larger size it will work and visa versa.

 

[74delta]

Awsome thanks for the information guys

 

[69PHOENIX]

Don't throw away the "742" There's always someone who will love an "Orphan" LOL And I think the Debate which was the Strongest of the two still Rages. Regards Tony.M

 

[74delta]

Don't throw away the "742" There's always someone who will love an "Orphan" LOL And I think the Debate which was the Strongest of the two still Rages. Regards Tony.M

Ow ya I'll keep it for sure and I have seen that debate posted many many times

 

[odcics2]

Mopar nascar b bodies used the 742, even when the 489 was in production.

They couldn’t afford a failure.

 

[74delta]

Picked up the 489 case today. 3.23 gears fresh clutches and bearings. $600

 

[polara71]

Picked up the 489 case today. 3.23 gears fresh clutches and bearings. $600

View attachment 398018

View attachment 398019

Perfect! Well worth it!

 

[john-9]

Picked up the 489 case today. 3.23 gears fresh clutches and bearings. $600

View attachment 398018

View attachment 398019

just so you know -- that is a cone style sure grip -- there are no clutches in that unit -- if the seller told you new clutches were installed ,,, i would be dubious of the new bearings were installed as well.

 

[oldkimmer]

Ask the seller for receipts. As mentioned that is a cone type. Doesn’t have clutches in it. Kim

 

[furious70]

Yup, unfortunately you may have double paid, $600 would be strong money for a rebuilt cone type or a good shape clutch type.

 

[74delta]

Yup, unfortunately you may have double paid, $600 would be strong money for a rebuilt cone type or a good shape clutch type.

Would have cost me much more to buy a gear set, cone or clutch type posi unit, and someone to assemble it! Now I also have a spare case to re sell or hold onto as a spare.

 

[furious70]

Would have cost me much more to buy a gear set, cone or clutch type posi unit, and someone to assemble it! Now I also have a spare case to re sell or hold onto as a spare.

your own cost to rebuild can be a useful gauge for how much to spend on someone else's parts - I'm telling you what the open market thinks of the prices. I asked $600 for the last verified low mi rebuilt 489 3.23 clutch type SG I had and settled for $525. Most cone type 3.23's sell for around $300-350. With a receipt for new parts it could be worth a little more. Local market conditions can drive the price up or down a bit since it can be $75 or more to ship a pig.

 

[74delta]

your own cost to rebuild can be a useful gauge for how much to spend on someone else's parts - I'm telling you what the open market thinks of the prices. I asked $600 for the last verified low mi rebuilt 489 3.23 clutch type SG I had and settled for $525. Most cone type 3.23's sell for around $300-350. With a receipt for new parts it could be worth a little more. Local market conditions can drive the price up or down a bit since it can be $75 or more to ship a pig.

Ya that's the first thing to pop up local everyone one fb groups and ebay would want around 1k before shipping for a rebuilt unit clutch or cone style