A. Manual 6-Speed (M6)
First, let me congratulate you on buying the stronger of the two stock transmissions. With minimal changes, this tranny in near-stock form has been deep into the tens. And in built form, it has propelled an F-body to mid-9-second glory. Now for the bad news. You also possess the single most part-destuctive force known to civilized man. FACT. M6 cars break more shit in the drivetrain then most A4 boys ever dream about. To avoid this (as best we can), we are going to talk about parts that are made ultra-tough, just to stand in defiance to this cruel tyrant called the M6 tranny.
1. Clutch
It's time to man up and start giving your left leg a serious workout. Your stock clutch (yes, even if it's a Z06 one) is weak. It is the skinny guy on the beach that all the other clutches walk by and kick sand in the face of. It will NOT hold much more than stock HP, and it won't even hold stock HP for long on sticky tires. If your plans are to run 11s or faster, then you can forget those oh-so-cheap Stage 1 and Stage 2 clutches. I hate the term "stage" because people get wrapped around the word and forget to think about what they are really buying. So you wanna be fast? Well, you have two choices of clutches:
Twin Disk
A Twin Disk clutch is very strong; it will most definitely get you where you want to be. It will also do so while retaining a very comfortable pedal feel, and streetablility. Sound good? It is. However, as always, with the good news comes the bad. It is well over $1200 for a respectable twin. If you want that comfort, you've gotta pay for it.
Sintered Iron Disk
Wow, just saying its name makes it sound manly, doesn't it? That's because it is. It's a MAN's clutch. Little pansy boys, who like to complain about too much rasp or the clanks and rattles that solid end links make, need not apply. If you do not love the feel of a race car, then DO NOT buy this clutch! But, if you want a clutch that will kick your car in the ass and say "giddy the fuk up pony!", then this is the clutch for you. Your reward for having balls? How does paying $400 less grab ya? Yeah, that's what I thought.
2. Driveshaft
First things first, you need to say to yourself over and over and over again: "ALUMINUM IS FOR BEER CANS, NOT DRIVESHAFTS!!!" When it comes to driveshafts, I will stand on this statement every day and twice on Sunday. If your plans include a lot of power and sticky tires, then you have three choices for driveshafts.
Steel
Steel is real. Steel is strong. Steel is easy to balance. Steel is afforable. Can anyone guess what kind of driveshaft I have? Thats right, steel. Steel, however, is not perfect; it does have two troubles. 1. It is heavy -- against its
lighter counterparts, it does produce slightly more parasitic loss. 2. In the rare occasion that they do break, they take a lot of stuff with them.
Chromoly
Chromoly... without going into a chemistry class, think of chromoly as having all the plusses of steel, and add to that it weights about 50% less. So why doesn't everyone have one? Price -- ah yes, the almighty dollar. These things are very pricey.
Carbon Fiber
All right! A real use for carbon fiber, other then making ricer hoods! Carbon fiber is light, very strong, and looks GREAT. One major asset that carbon fiber has that the other two do not, is that in the rare case that it does break, the fibers splinter and crack into what is best descibed as a broom. This means that as you are hitting the brakes and your broken driveshaft is still spinning, it is NOT hurting anything else. Hell, it might even clean off a thing or two.
3. Rear End
Let's face facts. When the General was building the F-body, he put no thought whatsoever into the choice of the 10-bolt rear. This rear is not even strong enough to hold the stock HP, and is one of the first things to break when a new F-body racer heads to the track. In the case of the M6 tranny, please do not make a $2500 mistake. If you have spent a week on LS1tech, then you have heard the words "12-bolt" and "9-inch" when it comes to rears. If you have an M6, then I want you to forget the first of those. You are about to spend $2500 on a rear; do you really want to break it? 12-bolts are for automatic cars. They last a long time in an auto. But you own the sledgehammer of parts, the T56, breaker of rears. For you, there should be only one choice -- the mighty mighty 9-inch.
Rear end parts... Now that you have chosen the correct rear, it's time to pick the parts you want in it. Most every place that sells these rears will give you these choices.
Posi-Traction: The best choice for a car that will not see much track time but still wants a super-strong rear.
Detroit Locker:The best choice for a car that will see a lot of both street and strip time. It is more noisy than the posi, but it is also stronger.
Full Spool: So you got a RACE car, huh? Well, this is what you want. Full spool is the least street-friendly of the choices, but it is hands-down the strongest.
Axles: The simplest way to approach axles is: the more splines, the better.
Gears: This is mainly a matter of personal preference. 4.11s are perfectly streetable while also performing well at the track. Numerically higher gears lean more to track use; lower leans more to street cars.