Let's talk 9" rears

[yellow wagon]

about to pull the trigger on a 9" from John's 9" Factory but want to get the right setup for the car. Here's what I am thinking of going with based on the fact my car is a basically a hot street car, will see a few trips to the track, no highway driving etc.

9" John's extreme housing
TrueTrac with 4.30s
31 or do I go 35 spline axles?
2 upper brackets
Drum brakes
1/2" studs

Is the TrueTrac the right differential to go with for my 90% street driving? Is it worth it to spend a bit more money and go with the 35 spline axles considering my car is 100% full weight, heavy etc? Or is 31 spline plenty? I know several guys here have the John's 9" including Ricky and Brian MRHP which I talked to a bunch about it at GLD a couple weeks ago. Looking to make this a winter project and just want some opinions.

I'll be selling off my stock rearend stuff if anyone is interested. The third member with 3.73s has all good stuff in it and I have one with 4.56s too, Dutchman axles with new bearings etc.

 

[1961BelAir427]

I would use a Detroit Locker over the True Trac. I have a True Trac myself to replace the spool in my 12 Bolt..... which I was all excited about until I read several complaints about True Tracs breaking in drag applications. I think you'd be fine in the elevens or maybe high tens, but if you are 60' footing really hard then it may give you trouble so why chance it? I believe the 31 spline axles would be enough. Lockers/posi units for 35 spline axles are kinda choice limited I think. There is also the 33 spline option for something in between. With the 31 spline axles you could keep a spare chunk without breaking the bank since those were available stock.

 

[scott hall]

31 should be fine for you. Does this mean your gonna sign up for Bowling Green now. We missed you at Great Lakes when the group was there.

 

[1961BelAir427]

I forgot to mention it, but don't forget to specify the 5 on 4.75" chevy bolt pattern. I've had friends that didn't think they needed to point that out and ended up with Ford pattern 5 on 4.5".

 

[yellow wagon]

I hadn't read anything bad about the TrueTrac online. Did read some negative comments about the Locker in primary street cars that they can be noisy, don't work as well in street applications etc but that's all just online reading. No real world feedback from anyone I know.

I want to go with the 1350 yoke also so I can step up to the Inland Empire big driveshaft too. I think that makes sense.

 

[Rickys61]

I hadn't read anything bad about the TrueTrac online. Did read some negative comments about the Locker in primary street cars that they can be noisy, don't work as well in street applications etc but that's all just online reading. No real world feedback from anyone I know.

I want to go with the 1350 yoke also so I can step up to the Inland Empire big driveshaft too. I think that makes sense.

Jason.. I know my motor isn't as big as yours, but I have the 31 spline with the Eaton.. Haven't heard a peep out of it on the street yet. I think she told me on the phone it was good for 750HP???So far, at the track it's been great.. I've been hitting it pretty hard.. Last time out my 60' were 1.88, my only regret so far was not going with more gear...
Rick

 

[BRYAN FUGATE]

I've had a 9" with detroit locker and 4.56 gears and 35 spline moser axles for 18 years now 10 of those on the street and track 8 years it was parked. Knock on wood have never had a problem. Noise has never been a issue either. I would consider discs for the rear while your doing it ( that's just my opinion)

 

[yellow wagon]

9" ordered today from John's 9" Factory! I'm pretty excited about it. Won't get around to installing it till later this winter but now I have something to keep me busy

Extreme Housing with 1/4" tubes
Magnetic drain plug
John's Nodular Third Member
TrueTrac with 4.30 gears
31-spline axles with standard length 1/2" studs (to fit under poverty caps)
10" drum brakes 5x4.75"
4th link bracket welded on

Lynn at John's 9" Factory has been great and answered all my questions. I'll post pics when it gets here in a couple weeks

 

[No409]

i run a 9" in my 55, 1350 yolk, 4.30`s, 35 spline, and a spool. If i have my et street`s on you barely notice the spool, reg street tires its very noticeable

 

[Rickys61]

9" ordered today from John's 9" Factory! I'm pretty excited about it. Won't get around to installing it till later this winter but now I have something to keep me busy

Extreme Housing with 1/4" tubes
Magnetic drain plug
John's Nodular Third Member
TrueTrac with 4.30 gears
31-spline axles with standard length 1/2" studs (to fit under poverty caps)
10" drum brakes 5x4.75"
4th link bracket welded on

Lynn at John's 9" Factory has been great and answered all my questions. I'll post pics when it gets here in a couple weeks

Congrats Jason... You won't be disappointed

 

[models916]

Does that 9" come with the pinion centered in the tunnel?

 

[yellow wagon]

Huh?

 

[MRHP]

Mine did. I believe unless specified differently they come centered.

 

[Rickys61]

Mine did too...

 

[BSL409]

Congrats Jason... You won't be disappointed

Congrats,

 

[63 dream'n]

Congrats Jason..........

 

[yellow wagon]

Still no 9"......seems the hold up is with having the housing powder coated. I should have just had them ship it to me bare and I could have gotten it powder coated locally for cheaper and in 2 days.

 

[MRHP]

I use the same powder coater as Johns, and they are horrible on their schedule. I have been put in a bind by them before. Sorry to hear of the delay.

 

[yellow wagon]

Its been sitting at their coater for 3 weeks now I believe.

 

[MRHP]

I had to damn near wait that long for one thing. 3 weeks is unacceptable in my book. I would be HOT! If I would have known, I could have brought it with me to Union Grove.