73 cuda 9 inch conversion

[Aussie-cuda]

Hi guys I'm thinking about putting in a 9 inch diff in my 73 cuda I've got a couple here at 1410 mm long or 55.51 inch dose any one know if the overall length will fit, I measured approx measurements and it seems ok I just have to move the mounts out a little approx 30mm any opinions??thanx regard Matt

 

[moparleo]

Are you talking about a "Ford" 9 inch ?

 

[Aussie-cuda]

Yes I think the overall length is the same and I have to measure the stud pattern but I'm told it's the same as well I'm going to put it on the hoist tonight and take some proper measurements.

 

[Chryco Psycho]

the 9" eats HP , not a swap I would consider

 

[DetMatt1]

Yep, unless you are completly out of 8 3/4s down there, I wouldn't suggest it either.
Ma Mopars 8 3/4 is a fine unit.

 

[Aussie-cuda]

Ok then,the diff in my car is a 489 case with a 323 posi bit it's single wheeling,the yoke appears to be small maybe it's a 318 diff?? Is there a difference?? And the uni's appear small as well.I might build a 3.5 posi if I keep that diff, oh and the driveline is a rebuilt mild 440 with a 727 that feels like it's got a stage 1 shift kit.

 

[Aussie-cuda]

Also what's the difference between 489 housing and a 741 ect are diff centers interchangeable? Thanx

 

[Brads70]

This is a good write up about them.
http://members.tripod.com/mojo_page/chry875.htm

 

[Aussie-cuda]

Thanx that was quite helpful,I can get my hands on a single spinner diff centre do you know if I can change it to a posi or is it better to just import a posi diff? Thanx

 

[Brads70]

Ya you can but I'd just get a new center section. I've built a few 9" Ford before but not a Mopar. I've never had any luck setting up used gears without having them howl. But that's just me I'm no expert. New gears no problem...used ones...no luck ! LOL

 

[Chryco Psycho]

I would just install a Tru Trac unit int a single wheel diff , the 741 is the lightest center section , small pinion , 742 or the 489 are stronger , you can use a conversion U joint to match up the yolk size , Doctor diff can help you out with complete gear assy if needed

 

[Aussie-cuda]

Thanx I'll see what I can dig up and do some costing, might build a Tru trac I'll have a think about it.