bart91406

Well I have been needing a new rearend fo a while, being that my car ran 11.50s last year, and I have made some improvements to the motor, but I just do not have the 1200 dollars to spend on a 12 bolt or 9 inch!

So I do some scrounging in the junk yard and find that a second gen camaro rearend is 1 inch more narrow than our cars, which will work out perfectly for me, I have some decent size tires, and have always wanted a little more backspace to my wheels, so a half inch per side should work out perfectly.

The reason that I will be able to do this swap is that I run lakewood lift bars, and do not need a tourqe arm. I know that some people on this board are not a big fan of these,but I have ran them for five years now and have always been impressed with the quality, and the traction improvement. These bars will lift the rear end and plant the tires, now depending on the control arm angle and the amount of horsepower, they may create to much antisquat for the racetrack with slicks and slightly slow down your 60 foot, but a 12 second car on the street will absolutely love the antisquat. I was able to hook up from a dead stop, loading the converter, on bfg drag radials, with no burnout, on the street, when I was running low 12s. So I will say that I really like these bars, and would reccomend them to other people, but everyone has there own opinion and experiences so to each there own.

Now that I have the rear end all I had to do was carefully, cut torch, and grind the mounts off of both rearends. After all the mounts are removed I center the new rear in the car, set the pinion angle, and double, then triple check all measurements, I tack weld the mounts on, then remove the rear to do the finish welding not lying on my back.

Now my car has a much stronger rear end, I bought the 8.5 for 200 dollars, I was able to reuse the posi, and just spent 200 dollars on gears and install kit. I was able to sell my old rear for 200 bucks so this was a really cheap upgrade for me!!

As far as the strenth of an 8.5 10 bolt, I know that it is not bulletproof, but you have to consider that the ring gear is onlt .375 smaller than a 12 bolt, and they share the same pinion diameter, and both rears use c-clips, so the only real weakness is the axles, which you can easily upgade with Mosers. If you were to use good axles, a stud girdle, and a high quality carrier, you would spend only the amount of a bare housing more than on your 7.5, and have a rear end WAY more durable. I have seen many cars run 10s on this rearend, and even heard of some going faster!

11seccamaro

im jealous gret idea.i blew my rear and got moser 9 inch for huge bucks .I have an 8.5 rear but couldnt figure how to make tracking arm work so i bought the moser.The 8.5 is a very stour rear i pounded my 454 elcamino with 8.5 rear for a whole smmer 7000 grand shifts with 4 speed blew 2 trannys but rear held no problem i think there as tough almost as 12 bolt.i dont think you will have a problem but i never had slicks on my elc which is what blew my camaro rear when i hooked up what engine do u have?stall speed? good luck.

crytical point

If you would of gone M-22 for the 4 speed you might have broken the rear first lol.

bart91406

A little more info for anyone considering this swap, All that is needed for this swap is a second gen camaro rear, and a set of the lakewwod bars. the lakewood bars replace the lower control arms, and eliminate the tourqe arm. You will just need to remove the coil spring and lca brackets from the 3rd gen rear, and weld them to the 2nd gen rear in the same location. The panhard bar mount is part of the driver side coil bracket, and will be retained.

These bars work in the same fashion as a ladder bar, but because of there short length, create a lot of antisquat. They do carry some of the drawbacks of ladder bars as well, most notably, binding. Because of the design of a ladder bar, the axle is not allowed to articulate. This is great for the drag strip and a straight launch, but when tranversing uneven pavement, the weight of the car will force the axle to articulate, and the bars will have to twist. This however is not a huge deal, I have driven my car everywhere and never notice the binding. Also, a lot of serious street strip cars use ladder bars on the street with no adverse effects.

TKOPerformance

I love the 8.5 10-bolt. It's as strong as a 12-bolt in my experience and much cheaper since they came in a lot of cars and trucks from the factory and were never stricty a high performance rear end like the 12-bolt. I know a guy who runs high 10s with one. I kept both the front and rear 8.5 10-bolt in my '87 Blazer and just built them up rather than do a swap to 1 ton running gear (D60 front and 14-botl rear) like a lot of guys I know have done. I have less sprung weight and more ground clearance than they do, and have yet to break anything with a 383 and 38.5" Boggers.

Don't be too sure about the M22 being super strong either. I've rebuilt plenty of them that have broken from a big block and traction. Back in the 60s Grumpy Jenkins used to swap the M22 trans in his Camaro after every pass just to be safe. They were the best thing going at the time, but today everyone runs an automatic, a Lenco, or a Jerico so they don't have to worry about breaking the trans.

crytical point

From what I have read the M-22 out of the early 70's were damn near impossible to break and for a GM trans to earn the name "rock crusher" is really impressive for a stock unit. I am just a fan of manuals and had my go with a automatic back when I would drag my 83, getting a bad launch was hard once I had the trans brake and the proper converter on it.

Though you could get a M-22 in 63 but the one im talking about was offered in 70-73 and had a close ratio and had a share of refinements over the early units. The unit was so stong that you only had to worry about everything around it in applications up to 1000hp.

Shagwell

I broke the "rock crusher" close ratio in my BBC '69 camaro more times than I can remember. My old man broke plenty to make a purist cry. Straight shift 2nd north of 7k and see what happens. After the 3rd one I just left the dent in the floor/tunnel from where the cluster shaft would hit after splitting the case. - I will note that I very rarely hurt a gear, usually just split the case. I ran one of the braced cases and it lasted a couple weeks. The aftermarket cases available now supposedly cure the issue. I simply switched that car to a Chrysler "crash box" and cured the problem.

All old-school anyhow. A well built T56 or TKO will handle more and are considerably more efficient in street cars.


Back on topic: Good luck with the "traction action" bars. Even under stock power levels, many people have torn the bracket. Personally, if you're going to run ladder bars, run ladder bars.

TKOPerformance

Not to hijack the thread, but here's the real story of the M22.

The first M22s (a run of 57 has been documented) came out in '65 (4/15/65 to be precise). The M22s were the first to use a 1" diameter countershaft (all Muncies got this upgrade starting in '66). The '65 M22 was in fact a factory modified #3851325 maincase that had the countershaft bore enlarged to accept the 1" shaft and the original casting number ground off (starting in '66 regular production castings were used once the switch across the line to the 1" shaft was made). All M22s also have the drain plug boss drilled and tapped for a magnetic drain plug (this was later adopted on all Muncies starting in '70). The biggest difference between the M22 and the M21/M20 is the use of low helix angle gearset (21 degrees on the M22 gears vs. 39 degrees on the M21/M20). The closer a gear tooth is to straight cut the stronger it becomes, but it also becomes louder. The tell tale gear whine is what earned the M22 the nickname "Rockcrusher". All M22s are close ratio (2.20/1.64/1.28/1.00) with the same tooth count as an M21. The M20 was a wide ratio (2.56/1.91/1.48/1.00). All M22s, and M21s/M20s, used a 10-spline input shaft from '65-'70. All Muncies switched to 26 spline input shafts starting with the '70 model year. All Muncies had a 27 spline output shaft from '65-'70, and switched to a 32 spline output shaft starting with the '70 mode year. The only exception to this is that the '70 Chevelles with 454s used 26 spline input shafts and 32 spline output shafts.

The weak link in the M22 was the case, as noted above, but what really killed them was how they were used. In a stock car, or even a modified car, on the street with street tires an M22 was nearly indestructable. But, so was an M21 from my experience. What killed a Muncie was traction. The M21 would always break first gear when you hooked it up on slicks. The gears just weren't strong enough. The M22 had much stronger gears, and rarely broke gears, but instead it just moved the problem to the next weakest link, which was the case. The aluminum they were using back then was nowhere near what we have today, and I don't think the factory cases were even heat treated. The design was done on paper, by hand without stress analysis. The cases were unreinforced, and not very strong, especially for their weight. The new Borg Warners and now Tremecs are computer designed and very strong; just look at all the ribbing. The Muncies are legendary because they were the king of the heap when they were new. The price they demand now and the fact that they just aren't that good by todays standards are why they are best left to memory and restorations. I'll admit that I have a soft spot for the Muncies. I ran them in a lot of different vehicles, and rebuilt more than I can count. If I had a '66 SS396 Chevelle that had an M22, or even an M21, I doubt I'd ever swap it for a modern trans. When it came time to find a suitable manual trans for my '86 IROC the Muncie was never even an option. I could not saddle a modern fuel injected car with 35 year old technology, even though I had a fresh M21 sitting on a shelf in my shop. I sold the M21 to a guy who wanted it for a restoration, and used some of the procedes to buy my T56. Times change, either you change with them or you die.

Shagwell

^ really good info right there. I was running an aluminum headed 427, 325 drag radials and am a firm believer that if you need to clutch to up-shift you should switch to an auto. I ran no syncros and cut every other tooth off the sliders and the engaugment teeth on the gears. They would up-shift like a mother, but were just like a dog-ring type trans coming down. I never hurt a gear or a slider, but I shredded some cases. - The chrysler boxes weren't particularily any better reinforced, but they were iron.

TKOPerformance

Yeah, that was the old school trick. Grind the synchro rings smooth (no teeth), and then grind every other engagement tooth off the gears themselves. I built a couple Muncies like that. Great for the strip, but they were all but impossible to downshift. They weren't particularly strong either, which is why companies like G-Force offer dog ring kits today, which are stronger, but still have that same slam shift ability on the upshifts. The downshifts are easier in a dog ring trans, but they are still a bit clunky. Jerico makes a clutchless trans now, and Liberty might as well. You have to drop the clutch to get moving, but once you are the rest of the shifts can be made without touching the left pedal. That's the ultimate stick trans. All the benefits with none of the drawbacks. Oh, and they have models good to like 2,000HP too : )

As you noted, the Muncies were the only "strong" trans back in the day that used an aluminum case. The A833s were iron, the Toploaders were iron, heck even the original T10s were iron. I guess GM wanted to save weight for some reason. As you noted though the iron cases weren't much better, and that was a material thing too. They were using cheap gray iron instead of the stronger nodular iron. It's like a 9" Ford case. The run of the mill ones are actually pretty weak (pocket bearing seat failure under load typically). The reputation of the 9" was built on the back of the N-case nodular iron rears that had 31 spline shafts and were used in the high performance stuff. Of course today most people start with an aftermarket case made from nodular iron, so it's a non-issue.

The Muncie, oddly enough, started to get phased out by GM in '73-'74. They opted instead to outsource their manual transmissions to Borg Warner who provided them with the Super T-10 (aluminum case) from then on. The Super T10 is pretty much the same as a late model Muncie in appearance and design. The Super T10 soldiered on into the 80s until it was eventually replaced by 5 and then 6 speed transmissions also built by Borg Warner (the T5 and T56). Sometime in the early 2000s TTC (Tremec) bought Borg Warner's transmission division and now all T5 and T56 parts are sold by Tremec. It's only bound to be more gears from here. BMW had a prototype M5 a couple years back with a 7 speed manual trans, but I don't know if it ever made production. I wouldn't be suprised to see 7 or even 8 speed close ratio transmissions in the next couple of years to get better economy out of smaller engines with narrower powerbands.

1983cameroman

hey what are your lift bar mounted to