Swapping out 8&3/4 for Dana

[entropy1049]

About to swap out the 8.75 in my '69 Road Runner for a Dana 60. Dana is set up as a bolt in exchange for the 8.75, so aside from drive shaft shortening, are there any other potential hiccups I should anticipate? Seems I may need to replace a drive shaft end, is this correct?

 

[PurpleBeeper]

I'm not "sure" if you have to shorten the driveshaft (others here know). There is some play in the transmission yoke end of the driveshaft, so if the dimensions of dana vs. 8-3/4 are really close, you might be OK. There are basically two u-joints for these years (big & little....3" and 3-1/2" roughly if I remember correctly). If the u-joint size is the same, you're golden. If not, they sell some conversion u-joints (one side 3", other side 3-1/2"), so you're still golden. FYI-I believe those conversion u-joints are stock in 1957 Pontiacs or Oldsmobile with the end caps swapped. The only thing I can think of that might hold you up is the speedometer gear in the transmission if the rear end gears are different.

 

[entropy1049]

I'm not "sure" if you have to shorten the driveshaft (others here know). There is some play in the transmission yoke end of the driveshaft, so if the dimensions of dana vs. 8-3/4 are really close, you might be OK. There are basically two u-joints for these years (big & little....3" and 3-1/2" roughly if I remember correctly). If the u-joint size is the same, you're golden. If not, they sell some conversion u-joints (one side 3", other side 3-1/2"), so you're still golden. FYI-I believe those conversion u-joints are stock in 1957 Pontiacs or Oldsmobile with the end caps swapped. The only thing I can think of that might hold you up is the speedometer gear in the transmission if the rear end gears are different.

Fantastic, this is exactly what I was hoping to learn. Thank you!

 

[Fran Blacker]

Dana swap is easy B body dana to b body car. As purple beeper said u-joints are the issue and drive shaft is to long. What size cup is on the dana and width of yoke . It could 1330, !.0625" cup 7290, 1.125" cup or 1350 yoke don't know size of cup on a 1350 off hand. 3.625" Outside to outside on cups. You can convert a 7290 to a combo u-joint by removing 2 cups of the 7290 and replacing them with 1330 cups. you need to do some measuring. I have a 68 GTX Dana drive shaft sitting around. 50 1/2" to 50 5/8" 7290 front u-joint and a 7290 on rear of shaft and 1330 cups for yoke.

 

[entropy1049]

Dana swap is easy B body dana to b body car. As purple beeper said u-joints are the issue and drive shaft is to long. What size cup is on the dana and width of yoke . It could 1330, !.0625" cup 7290, 1.125" cup or 1350 yoke don't know size of cup on a 1350 off hand. 3.625" Outside to outside on cups. You can convert a 7290 to a combo u-joint by removing 2 cups of the 7290 and replacing them with 1330 cups. you need to do some measuring. I have a 68 GTX Dana drive shaft sitting around. 50 1/2" to 50 5/8" 7290 front u-joint and a 7290 on rear of shaft and 1330 cups for yoke.View attachment 378618 View attachment 378619 View attachment 378619

Thank You very much! These two posts have provided the information I was seeking.

My yoke is a 1350. No gear change (4.10 to 4.10)

Thanks folks.

 

[Fran Blacker]

I think the cross shafts to all three u-joints are the same 1330, 1350 and 7290. The 1330 and 1350 have outside clips and 7290 has inside clips.

 

[Shorthorse]

Set up or removed from a running car? In any case you might have to deal with the dreaded and often posted about "pinion angle". Make sure you check it.

 

[entropy1049]

Set up or removed from a running car? In any case you might have to deal with the dreaded and often posted about "pinion angle". Make sure you check it.

Set up, never been installed. Searching now for "pinion angle" on the board lol.

 

[Cranky]

Drive shafts for the Dana are generally a bit shorter than the 8 3/4 shaft but yours might already be on the short side so put it in and check. I like at least 1" of the slip yoke showing....anything less, you'll need to shorten it.

 

[entropy1049]

Drive shafts for the Dana are generally a bit shorter than the 8 3/4 shaft but yours might already be on the short side so put it in and check. I like at least 1" of the slip yoke showing....anything less, you'll need to shorten it.

1", gotcha.

 

[Fran Blacker]

Drive shafts for the Dana are generally a bit shorter than the 8 3/4 shaft but yours might already be on the short side so put it in and check. I like at least 1" of the slip yoke showing....anything less, you'll need to shorten it.

Cranky most seals I have seen dust covers. What about them?

 

[Cranky]

They are pretty flexible but you can allow a little extra for them so they will last a longer.....

 

[entropy1049]

Dana went in slick as can be. Drive shaft shortened 1&1/2", 1350 yoke end welded on, shaft balanced. Piece of cake. Thanks for the tips!

 

[mopar 3 B]

Now that you are draging extra weight around how do you like it?

 

[entropy1049]

Now that you are draging extra weight around how do you like it?

LOL! Can't tell a damn bit of difference from the 4.10 Sure-Grip 8&3/4 that it replaced. But it looks sexy

 

[khryslerkid]

LOL! Can't tell a damn bit of difference from the 4.10 Sure-Grip 8&3/4 that it replaced. But it looks sexy

And you shouldn't notice anything different in the gearing. Maybe a little better traction, being the Dana is a bit heavier? (I wonder how much heavier the Dana is?)

I did the same swap years ago in a '64 Polara 500. But I went from stock to a 4.56 Yeah Baby!

They do look bad ***!

 

[mopar 3 B]

We could open the sprung verses unsprung weight debate. But we all do strange things for the sexy look.

 

[khryslerkid]

(I wonder how much heavier the Dana is?)

The Dana 60 is 35 pounds heavier than a 8 3/4...

Total weight, fully assembled unit, 240lbs. (By a poster who weighed it himself)

 

[not so famous bob]

The Dana 60 is 35 pounds heavier than a 8 3/4...

Total weight, fully assembled unit, 240lbs. (By a poster who weighed it himself)

w/ a caltrac system, it`ll be a little lighter due to the single spring

 

[khryslerkid]

w/ a caltrac system, it`ll be a little lighter due to the single spring

And I believe there are lighter axles available also.