martindforsythe

Check out my first post if you want to see the build specs on this car (link below). It's a mint 84 Bird that has been in storage for the last 17 years. 80k original miles. New 383 engine HP will be somewhere in the 525 range, I won't know for sure until I take it to the dyno shop and tune it right. 700R4 transmission. I was at first looking at a Moser Ford 9" package. But, with the options I wanted it was going to cost close to $4000.00. I can get pretty much the same thing in a GM 8.8" from Hawks for about $2700.00. Any arguments for or against either one or both?

https://www.thirdgen.org/forums/engi...ml#post5994037

big gear head

GM 8.8, do you mean a Chevy 12 bolt or is this a Ford 8.8?


Some people have complained about floor clearance with the 9 inch on lowered cars. That's the only problem that I know of with it.

martindforsythe

Here is the link to the GM rear end I'm talking about. The car is not going to be lowered. So, the question is....Is it worth saving a thousand dollars to go with a complete GM 8.8 rear end with disc brakes?

http://www.hawksthirdgenparts.com/ha...-end-assembly/

big gear head

That is not a GM rear end, it's a Ford 8.8 that has been modified to fit the 3rd and 4th gen GM F body.


Have you looked at a Moser, Strange or Mark Williams 12 bolt? They all make a bolt in Chevy 12 bolt for the 3rd and 4th gen GM F body.

martindforsythe

My bad. You are right. That is a Ford. Is it worth $2700 complete with Yukon Duralock Differential, Moser 31 spline axles, 3.73 gears, disc brakes, brake hoses, calipers, sway bar mounts, and backing plates. All completely assembled and ready to go?

articwhiteZ

iTrader: (56)

for that price you can get a Currrie Enterprise 9" ford Detroit Locker any gear 31 spine axls bolt in..shipped

martindforsythe

Thanks. I will check them out. Any time I can save money on this build I will sure try.

SbFormula

Yep with lowered 1inch, Moser 9 inch could bottom out and hit the floorpan... Nice noise when it happens!!!

martindforsythe

I don't plan on lowering the car. I'm stuffing some pretty big rubber underneath. I'd like to keep it as stock looking as possible. But, keeping 550hp under wraps once it is started will be hard to do...

SbFormula

Makes sense. Had I known, I would have modified the OEM rubbers so the axle would have stopped before hitting the floorpan. Having said that, by going with Koni shocks, it barely happens anymore. But the floorpan is now shaped after many hits... kinda made its own clearance by necessity ha ha ha!!!

martindforsythe

I'm calling Currie in the morning. Maybe I will have to cancel my Hawks order. We'll see what king of price they can come up with.

antman89iroc

So what did you decide? I am considering a rear end swap. I like the 8.8 too. I do like the ford 9" but it is a lot of rear end very bulky as others have noted. It seems a 12 bolt of 8.8 would be a better fit.

martindforsythe

I went with the 8.8" from Hawks third gen. Comes with Moser axles, a complete disc brake package, and all the factory brackets. Backing plates are extra, unless you have your own to send to them. I opted to go with the Yukon street locker differential and 3.73. gears. $2843 total cost. About $1000 less than a 9" set up the same way. Call hawks third gen between 1pm and 5pm eastern time and ask for Bruce or dial extension 2101.

antman89iroc

Is it a quiet gearset and what is your experience with that posi unit?

I think the 8.8 is strong enough without going to the big 9". Don't get me wrong the 9" is super tough but may be overkill for a street car where the 9/10 bolt just isn't quite strong enough.

SbFormula

Mine is definitely overkill...

martindforsythe

If you aren't using a trans brake, the 8.8" should be good for 550hp at the flywheel (automatic transmission) with the yukon duralock street. If more hp than that or using a trans brake, go with the yukon duralock pro. As far as noise, you'll have to ask me in a month or so when I get it all together. It's a big project. Engine, transmission, rear end, fuel tank, drive shaft, a ton of UMI Performance upgrades, and all the little thing$ required to make it all happen.

antman89iroc

Lol fair enough, projects take time. Thanks for the input and keep us posted.

I notice on the 9 bolt that the factory gears are very quiet but the aftermarket gears are noisy. At least mine are, mostly on coast/decel. Under power it's fine. The gear rep seemed to think it is "normal".

A bit off topic but I have heard that gear sets with even numbered teeth on the pinion are noisier than gear sets where the pinion has an odd number of teeth.??? 8.8 and 9" rears have a lot of gear sets available so one can chose the quality level quite easily. With the 9 bolt we're sort of stuck with used factory, Yukon 3.70's or I believe there is a source in Australia. You can't just chose a set from Summit.

Podium

iTrader: (2)

You can get a complete moser 31 splines and wave trac for 2800 shipped. Call brute speed or Midwest Chassis. I was in the same boat. Thought about Hawks 8.8 until I saw that price tag.


2800 for a 8.8 is ridiculous, even with brakes.

martindforsythe

Midwest Chassis base price is $2999.00 per their web site. Of course that is a 9", they don't have a listing for for the 8.8" If you include disc brakes, backing plates, an optional center section, and assembly, it's over $4000.00.

The Moser 9 Inch with Wavetrac for 82-02 F Body from Brute speed is $3075.00 without brakes or any options. It will still be a $4000.00 rear end when all is said and done.

I got these prices right their web sites. So, how do you get one for $2800.00 ? Please post a link to where you saw that price. I still have time to cancel my Hawks order.

Podium

iTrader: (2)

Bob at brute speed is offering the wave Trac as the same price as a true trac or what ever the Eaton piece is called. He is a great guy and will work with you and your price range.

Midwest chassis will match anyone's pricing in on moser, strance or antubing else they carry. After talking with Eric the owner i ordered through them.Sorry, I should have been more clear.

I am piecing together a nine inch I will put together myself. I will be around 2500 shipped. I got my center section for 1350 (posi, 31 spline 4.30s,). The housing and axles are around 1200, less or more depending on options.

You can save money by not having it powder coated too. That's the route I'm going. I will por15 the housing . Will only be about 30 bucks to do so.

If you want brakes, you can get ls1 brakes for 200-250 shipped complete. Ebay normally always has them.

martindforsythe

I now see where you are coming from on this. You can save money by putting it together yourself, but the experiences I have had with the Ford 9", if you don't get it perfect, you eat up a set of gears really quick. After that, you buy more gears and try again. The 8.8" from hawks will handle the HP I have and if there is a problem, it's covered by them, all it will cost me is shipping and time.

Podium

iTrader: (2)

They set up the gears . The 9 inch is the easiest rear end to work on. Look on brute speeds website. Thy have full instructions.

//<86TA>\\

iTrader: (14)

9" no question, not even a choice really

Confuzed1

iTrader: (4)

Mine hit at stock ride height. It just gets worse if you lower it. If you carry people in the tiny back seat, it'll really slam the floorboard....or with no one in the back and going over railroad tracks.

It eventually seems to "clearance" itself to an extent. It's just the shear size of the 9" as compared to the 10 bolt stock rear....the 9" is huge in comparison...but we're making it fit where that teeny 10 bolt was. At least in my case, it's the upper corner of the torque arm mount that hits. It'll dent the floor under the rear seat. I suppose one could cut out a small round section right where it hits, and weld in something like an inverted bowl for additional room...

SbFormula

(...) by going with Koni shocks, it barely happens anymore. But the floorpan is now shaped after many hits... kinda made its own clearance by necessity ha ha ha!!!

antman89iroc

Another option I just found is Strange's Dana 60. It's stronger than all other options but is more efficient than the 9 inch ford. All setup with 35 splines, posi and spicer gears set for ~2800. Just add brakes. If they are all about the same price why not go for the stronger rear? The only penalty I see is about a 25 pound weight gain over the 12 bolt and 15 over the 9 inch. It really seems to end up a matter of preference. If you want "quick change" and a super wide gear ratio selection then the 9 inch is hard to beat. If you want the strongest then the Dana is the way to go. If you prefer "GM" type then the 12 bolt is your option. I really like the idea of the 8.8 Ford rear but since it is about the same cost as the rest (Bruce quoted ~2700) then it isn't as attractive.

antman89iroc

Oh I forgot to mention the Strange 12 bolt "drop out" chunk for the Ford 9 inch housing. That's an interesting option too. What's the old saying, "how fast can you afford to go"?

There really are a lot of options, just no factory "take outs" unless you stumble across a Dana 44 somewhere.