98cherrySS

iTrader: (2)

My 10 bolt is about done and I'm looking at the aftermarket for the best rear end for my needs. The info on the car is in my sig. The car is 95% street driven and it sees the track once or twice a year. I do beat on it pretty good on the street and I plan on spraying it soon. I expect ~600rwhp on spray.

My goals:

Priority #1 is that it be quiet. No whining and no clunking. Just silence.
Priority #2 is durability. The car is equipped with DR's but I will run a slick at the track. I like to drive the car to and from the track.
Priority #3 is budget.
Priority #4 is traction. No spools. Wavetrac is probably too expensive.


I'm thinking about a 9" and running a 3.90 gear instead of the 4.10 that i currently run.

How does a 9" feel compared to a 10 bolt?
Does it drive differently?
Should I consider a 12 bolt?
Is there another option I should consider?

Thanks,

Randy

Bob@BruteSpeed

iTrader: (16)

The factory 10 bolt that came in these cars has a very small 7.5" gear. A variation of this rear was used back in the '70's in the Chevy Monza, then in the Chevy S-10. GM had to of known they would have warranty claims when they decided to use this rear in the 3rd and 4th gen f body's, apparently the cost of creating a stronger rear was higher than what they thought the warranty cost would be. This has been a real plus for the aftermarket, as a bone stock LS1 F Body with a manual transmission can break one of these 10 bolt rears! Many people have tried to beef these 10 bolt rears, spending a lot of money in the process. What they normally end up with is a rear that still breaks, as everything on these rears is too small.
The 12 bolt rears that are available for these cars is a step in the right direction. The 12 bolts are well known for being a stout rear that was a factory option back in the day in many performance cars. You can have a 12 bolt in an early Chevelle, Nova, Camaro, etc, and beat the snot out of it and not hurt anything. Put a 12 bolt into a late model f body that uses a torque arm, make a couple 4000 to 5000 rpm launches at the dragstrip, and I can just about guarantee you'll have a lot more gear noise on the way home. The torque arm seems to distort the housing on the 12 bolts, and it seems to happen to all the brands of 12 bolt rears. This does not happen to the 9 inch rears, and there is no price difference between the 12 bolt and nine inch rears. As the horsepower in our engines keep escalating, most people these days go straight to the nine inch rear. The 9-inch has an internal rear-pinion support that also supports the gear end of the pinion to limit gear deflection under high torque loads. This seems to be the major reason why the 9 inch doesn't start whining after high rpm clutch dumps, when the 12 bolt will pick up noise. The 9-inch locates its pinion gear lower on the ring gear to improve tooth contact, better the 12 bolt does. The 9-inch also has a 0.125-inch larger ring-gear diameter and internal pinion support than the 12 bolt.

http://shop.brutespeed.com/Moser-9-I...c-Truetrac.htm
Please take a look at the link here and let me know if you have any questions. Bob

speedtigger

iTrader: (16)

I have the Strange S60 behind a lot of power and it is dead silent on the street and I have no worries of ever breaking it.

MidwestChassis

iTrader: (5)

I think the strange S60 is probably the best bang for the buck rearend on the market today. Give us a call if you have any questions.

MidwestChassis2

iTrader: (1)

To answer your questions in order.

#1 You can not expect aftermarket rear ends to not have some whine, performance gears will always be a little louder than factory. Some brands worse than others.

#2 Like Bob mentioned if you want durability stay away from the 12-bolt you mentioned. Look into a Strange S-60 or the Midwest Chassis fabricated nine inch. We can set you up with rear ends from Strange, Moser and of course the most popular option on the market is the Midwest Chassis Fabricated nine inch. It is the only rear end on the market that bolts in just how the 10-bolt came out.

#3 Aftermarket, Quality, & Budget are not three words that go together. The closest you will get to putting those three words together is the fact we allow customers to do a $500 deposit on a rear end and pay as you can interest free until it is paid off. This has helped hundreds of our customers get into a quality rear end.

#4 Traction is not an issue but you do want to stay away from Truetracs, or clutch style posi's and Detroit lockers. As they are known to have long term issues. We have a differential now that is not as costly as Stranges S-Trac or the Wavetrac and has proven to hold up rather well.

If you have questions feel free to contact us at (309)382-6252 as we prefer to talk to customers one on one when it comes to rear end purchases.

onyx_rock

iTrader: (8)

Just put a Strange S60 under mine and like it so far. no noise but only in break in period now. super easy install.

mjs1012

iTrader: (36)

+1 for the S60. I put one in my car and it is overkill, but that's always fine lol. I have it with the s-trac diff and it's very quiet.

98cherrySS

iTrader: (2)

Thank you you for taking the time to address each of my priorities. I'll give you a call today or tomorrow.

98cherrySS

iTrader: (2)

Did the S60 change the feel of the car in any way?

mjs1012

iTrader: (36)

I couldn't tell any difference.

MidwestChassis2

iTrader: (1)

No rear end will make the vehicle feel much different but what you need to look at is some quirks certain rear ends have. One of the problems a stamped nine inch has is the torque arm makes contact with the floor board and can happen with a S60 if your vehicle is drastically lowered.

We eliminate this issue with our fabricated nine inches with how our torque arm is design. Which is included with our package.

The S60 is a great rear end and our next go to for customers. We sell them weekly. A lot of it depends on budget.

98cherrySS

iTrader: (2)

Kevin, I really appreciate your time on the phone today. Thank you for answering all of my questions.

Squirts11

iTrader: (14)

Just got my s60 and I can't wait to get it in the car. MWC guys are very knowledgeable and I would do business with them again.

MidwestChassis2

iTrader: (1)

Glad you are happy and as you can see we always have the best prices even on the S60 and always willing to answer questions before, during, and way after the sale.

01ssreda4

iTrader: (96)

I really gotta disagree. 600hp is NOT out of the realm for a 12 bolt to be seriously considered. I've been happy with mine.

98cherrySS

iTrader: (2)

The 12 bolt options have been seriously considered. I want this to be the last rear end I buy for this car.

MidwestChassis

iTrader: (5)

There is a huge difference between a 6spd and auto when it comes to what a 12bolt can handle I would not have an issue using the 12bolt in most cars with and auto and a small converter but you put a 12bolt behind a heavy 6spd car with hard launches at the track or abuse on the street the 12bolt starts to become an issue.

weedburner

Doesn't have to be a big difference between 6spd and auto. In fact a 6spd can be easier on the rear than an automatic, as it does not have that initial surge of converter induced torque multiplication. Properly slipped, a clutch can deliver your best launch while putting no more stress on your drivetrain than if you were roll racing...see many 12 bolts damaged while roll racing?

The OP can be quicker/faster with the 12 bolt, it's just more efficient than the 9" at his power level.

Snake_Skinner

iTrader: (12)

^ What's this differential called?


And what's more efficient: S60, mwc fab 9, 12 bolt?

01ssreda4

iTrader: (96)

12 bolt will be more efficient due to weight and gear mesh pattern. However its negligible, meaning get the rear end you want. Longevity is the name of the game for most not if you're leaving a few ponies on the table. I went 12 bolt because I will likely never break it and if I do I can fix it without paying someone.