vortec350s10

[QUOTE=antman89iroc;6104314]Vortec350, how's it holding up now? I am in the process of doing basically the same upgrade so I've been reading up on your thread

Hey antman,

The rear end is still holding up just fine. I've got plenty of miles on it and had beat the **** out of it and no issues. So far my best 60 fts are around 1.62's.
I change the oil on it again this summer and everything looked great. There's still a little bit of a whine but it's still the same from the very first day that I installed it.

As far as the tendency to be noisier with "hunting" gear sets I really have no idea. But I doubt it would make much difference. My gears are 3.25 and I'm pretty sure they are a ratio where the teeth on both gears are always touching the same ones.

antman89iroc

Did you notice any difference in ride height after installing the 9 inch rear? I just finished mine with a Moser housing and it seems to be sitting 1/2-1" higher than before. I didn't measure it prior to the swap so this is subjective. I noticed the rear end tubes are larger and the spring perches are beefier so that could affect the height slightly.

vortec350s10

I don't think my ride height changed at all. I don't believe I measured the distance between the axle centerline and the spring perches so I can't speak to that. I guess it all comes down to that dimension, if it's the same as your old housing or not.

antman89iroc

Thanks. The centerline-to-perch dimension would affect ride height. Could the orientation of the perches vs the pinion centerline (from the side view) have an affect as well? Since the spring is mostly behind the vertical centerline, as the pinion drops in the front the spring perch would rise in the rear which could also have an affect. Additionally, as the housing is rotated (to adjust pinion angle) it moves fore and aft which changes the alignment of the upper and lower spring perch. The further down the lower control arm is mounted to the housing the greater this affect would be. All are small changes but could add up to a noticeable difference. Theoretically anyway.

vortec350s10

I could see those other details effecting the ride height a little bit, if the differences stacked up in the same direction. Did you have to do any clearancing to your floor to clear anything? I checked mine with the rear end bottomed out (no springs) and after driving it still touched the areas I beat in a little.

antman89iroc

I checked against some old pictures of my car and it is higher in the rear than before. I have also added air bags in the rear but they are deflated now. I suppose they could be adding to the ride height even with only 2 PSI in them but they feel soft. The Moser spring perches have a tall center tube which compresses the bags more than the stock perches would so that could be a lot of it. I just didn't expect them to have any affect with almost no pressure in them.

Yes, I did clearance my floor pan/tunnel some right where the upper bolt would hit. I raised the rear up without the springs and held it at the correct angle. It would hit if compressed all the way but hasn't yet (that I have noticed) in the ~150 miles of driving so far. I have my pinion angle set at +5* nose up which should move that point back some. My engine/trans sit -5* tail down so I had to adjust to match. I didn't build any angle in for pinion rise on acceleration.

BTW thanks a lot for your original post. I referred to it a lot during my parts selection and build. We ended up with very similar setups Moser housing/axel, Yukon carrier, True track and Motive 3.50's. The main difference is I reused my PBR rear brakes that came stock on the car. I am very pleased so far.

vortec350s10

That's cool to hear that you are happy with it so far and that my thread helped! The 9" definitely adds a lot of weight to the car, and they say it is less efficient as well. I'm curious to know if you notice your car being any slower after installing it. Obviously this is only possible if you have kept everything else the same to do a back to back comparison. I went from 3.42's in a 10 bolt to 3.25's in the 9" and it seemed to slow my car down quite a bit in the 1/4 mile. If we never break them I think it's an ok trade off to have one less thing on the car to worry about.

antman89iroc

Yes, your thread did help. It's threads like this that help motivate me to add more detail when posting and sharing my experience here and on other threads.

Weight, yes it does add quite a bit. I weighed my BW 9 bolt at 165# wet, less brakes and sway bar. The 9 inch came in at 217# in the same config. So an additional 52# un-sprung. The Yukon carrier was noticeably heavier than a stock Ford but I didn't weight them. Of course the housing and that massive torque arm adaptor were all factors.

Performance. I haven't been to the track yet to quantify so I may have to modify the following later. In the past modest gear ratio changes didn't make much of a difference in the 1/8mi. Going from 3.27 to 3.70 was about 0.05 sec gain. I don't expect 3.70 to 3.50 making much difference and could possibly net a gain since I now have a larger CI motor with more power. I expect the traction consistency and not fearing to lay the wood to it off the line may help minimize any efficiency loss as far as ET goes. The real test of power loss may be the MPH trap speed. Also, in the 1/8mi the car would trap in 3rd gear but I would have to push the RPM because I didn't want to push in the clutch 50 feet from the end to shift. I am hoping the taller gear keeps me in the power band a little better.

I was always afraid of breaking the stock rear so I launched at 22-2500RPM and drove it out of the hole. Also, even though I had a "good" posi unit it would occasionally spin the left or right side depending on which one broke first. ET killer. My 60ft was in the high 1's ~1.80-90's if memory serves. From a traction stand point I think the extra weight may actually be a benefit. Like you said it's the peace of mind of having one of the strongest rears that helps.

One of my highest priorities was having a quiet running gear and dropping the cruise RPM a little. It's a home run in those points. 3.70's was a little too low in my experience for a fair weather daily driver. The cost of installing a helical gear differential, 31 sp axles and 3.45 gear in my BW 9 bolt was approaching $1600 with all related components and I would still have a 7.75" rear. I spent about $2400 on the 9 inch and feel the extra $$ was worth it if only for bragging rights.

ASE doc

Hi, I'm installing a 9 inch Ford and I have the same LS1 rear brakes. It looks like your LS1 caliper brackets bolted on okay. I'm concerned about bolt hole spacing on the axle ends. I got the rear brakes from Fly N Bye. They bolted right up to the 87 factory rear axle. The closest axle tube ends available for the 9 inch are 93-02 F body. I don't know if there's a difference. Did you run into this issue?

vortec350s10

ASE doc

I'm planning on using Quick Performance. A friend used them on his Chevelle and had great success. I plan on ordering the housing and axles on Monday. I looked at Moser and didn't see an option for axle end flanges that included 87 M/Y. I don't know what the difference is. I'll talk to the folks at QP before I order to be sure. My brake kit is listed in Fly N Bye's catalog as the "LS1" rear brake kit. They are the rear brakes of a 2002 Z28 / T/A. I don't know what was done to the brackets to fit the 87, if they were custom made or just modified. They appear to be the factory brackets.

QP's fabricated housing is 10lbs lighter and, they claim, 30% stronger than the Ford factory housing. I'm planning to use the Yukon aluminum case. It's about 20lbs lighter than nodular iron. All together, the unit should come out close in weight to the factory 7.5" and be good up to 700hp, according to QP. I have heard the aluminum case expands more with heat and might be louder than the iron when warm. But, I figure that pretty much every road or circle track racer runner a 9" Ford is using an aluminum case so they mustn't be too bad. The guy I talked to at QP didn't mention any concerns about noise or durability on the aluminum case. I will ask specifically about this before I order the case. It will be a few months before I order that unit, I have time to do more research and make a final decision. From reading your thread, I'm going to go to 3.50 gears instead of the 3.25. Better to err to the side of higher numerical.

vortec350s10

Well it’s been a couple years since I posted here. Today I decided to pull the third member to fix a small but annoying oil leak at the gasket to housing. My sharpie notes on the pinion support said I last changed the oil in 2016 so it was probably overdue anyways for some clean oil. The rear end has been the same since I last posted. Same noise at always. Not better or worse. Anyways there was quite a lot of silver glitter in the oil when I drained it. More than I was expecting for sure. After yanking the gears out, they look kind of worn/rough on the surface but the backlash still feels tight (didn’t measure). So it went back together with a new gasket and sealant. I did take a closer look at the little bit of end play in my axle shafts and noticed my tapered roller bearings don’t get tight with the backers bolted onto the axle flanges. There is probably a 1/16” or more end play and since they are tapered bearings that end play allows the axle to move up and down too, distorting the axle seals. So I need to find some shims to place between the bearing race and the housing. The shims need to be about 3” OD and no smaller than 2.5” ID. I haven’t found any online that spec this size. Lots of shim kits out there for different applications but they usually don’t have dimensions listed. If anyone knows what might work for this please let me know!

Don’t know how I had so much ambition years ago to tear this thing out three times in one summer. Even with a lift now it still sucks lol