Rite axle for a 700-800hp fbody


#1

im just looking for opinions and axles setups that have or havent worked for people. feel free to post links. im currently looking at moser 9" axle there quite expensive at about 3500$ plus. also please dont post to google search it ive done plenty of research im just looking for real people opinions. my setup is t76 turbo on built up lt1 firebird mcleod twin disc clutch with a stock t56 behind it.


#2

I was a drag racer for many years and the most popular differential then was a Ford 9 inch. They were very plentiful and fairly inexpensive back then. They were also basically bulletproof.


#3

Concur w/ @missileman . I have the Ford 9 inch locking differential on my early 70’s 4x4 truck’s back axel, and it really is bullet proof. I’ve pulled tree stumps etc, never a complaint from the axel. I guess it is true back then when Ford said they built their trucks “Ford Tough”.


#4

cool thanks guys what do you think about the diff ive been looking at wavetrac or a nice limited slip because its going be mostly a street car. i was thinking of swapping in a spool if i run it at the track with some real tires. also wavetrac has a limited liftetime warranty i dont know exactly what that means but they are expensive. ive heard good and bad about the tru trac and alot of people like the detroit locker but ive heard there kind of a rough feeling diff which being a street car i wouldnt mind spending a little more and get something that will last and i will like.


#5

Rearend is pricey? Isn’t a 700hp motor also pricey? Keep ur tires narrow and u will never hookup so u won’t need a beefy rear. Ur tires will just spin.


#6

When you get into that kind of specifics, one brand vs. another, etc. on high performance rear axles, you might want to try a specialist forum, also are there ones associated with the different vendors (Jegs, etc.)? There are some folks here that know about that equipment, but I’d think a forum that specializes in it would have lots of additional info.


#7

thanks texases i have posted on ls1 tech and looked through moser and did alot of google research just though i would see what people on hear have to say


#8

That’s great, sounds like you’re doing just the right things.


#9

@cavell the motor is already built and running lower boost in the car it was over 10k to build it. the stock axel is wining, leaking and knocks back and forth a little im assuming i smashed the crush washer but either way the car is grounded until i get it replaced. i had my fun but its not worth ruining the car driving it the way it is


#10

Watch the latest bitchin cars show. They did 2 different f-bodies with 9 inch rearends. It’s on velocity channel


#11

FYI for the OP: Rear axel technology assessment is a common topic in the magazines “Classic Trucks” and “Peterson’s 4 Wheel Drive”.


#12

9 inch with a TruTrac would be a streetable limited slip. The worm gear diff is similar tp the Torsen standard in later f bodies. If you build a second pumpkin for the drag strip, spool it. They are easy to swap on a 9 inch.


#13

That 3 and 4 grand would be pretty tough to take unless it’s a strip car with sponsor names on the body panels…

My opinion would be to use a stock Ford 9" and tweak it a bit at most. Around here I’ve seen 9" rear ends go for 100-200 bucks. The last rear end I bought was a 12 bolt Chevy non-Posi and I gave 125 for it; drum to drum, inspected, and ready to go.

Of course with a Ford 9", dual clutch, and tires that dig in, then the weakest link in the chain might be the stock transmission. :frowning:


#14

Or the driveshaft…

$3500 for the Moser set up seems high.
I’ve found that once you get over the 600hp hump, it starts getting expensive fast unless you’re willing to do your own work and beef up stock parts as much as possible, saving the real cash for the internals that you can’t change (axle diameter, splines etc).


#15

I think part of the big money for the axle is the car itself. The correct brackets need to be welded on, like any axle, but an F-car car needs a mount for the torque arm, too. This is a bracket that needs to surround the U-joint area to attach a central arm leading to the transmission. On the stock axle, it is part of the diff casting.

Typical ready to add brackets housings only run almost $1000, the assembled pumpkin runs $1200 to $1500. Add in brackets and brakes and you are about $3500. Speed costs more money today than it used to. $3500 ready-to-run sounds like a decent price to me.


#16

it was 1355$ for the housing which seemed reasonable but then you tack on 1675$ for the center section with middle priced diff 400$ for the torsion arm and 400$ for the drive shaft it adds up quick. i dont mind spending the money but i have been looking at all options i think one of my buddies said i can use a Strange center section but i haven’t looked into that yet


#17

@mustangman ha your post landed rite before mine


#18

I guess we have different ideas on what constituted an “axle”. Including brakes, driveshaft?

Most of the crowd I hung around with would call it an axle assembly when talking about a loaded, RTR rear with the housing, axles, center, etc. At first, I thought the inquiry was for just that, axles but realized you were going after something more as I read further into it. Didn’t think it was also the diff, brakes and driveshaft…

I never bought a commercial RTR package but preferred to either fabricate my own stuff from stock parts or in a couple cases, bought a specific axle housing from Art Morrison pre-fabricated for the application. Then I went out and bought the individual parts I wanted to stuff it with.

It’s not like its a unique situation to mount a 9" in an Fbody. I’m betting there are quite a few places you can get a drop in axle housing. Like anything, you can spend any amount of money you want by upgrading this and that. It can be a challenge to remain grounded in what is actually necessary for your situation…BTDTBTTS.


#19

ok4450 My old 1963 Ford Galaxie 406/405 was factory equipped with 9" rear plus Borg Warner aluminum case super T-10 4spd. Talk about bullet proof! Probably more like bazooka proof! Of course at nearly 4,000 pounds and 2.75 to 1 rear gears it was not much of a drag racer.


#20

cool thanks guys i was considering fabricating one out of the scrap yard but at higher horse power im thinking the insides might have a little trouble and a company like moser makes racing insides like axle shafts. so maybe the housing would be the only thing to hold up but thats the hard part to get rite considering you’d have to cut the tubes and weld on new ends and bracket with precision and also its the only part i considered reasonably priced.