well, i'm getting ready for the summer buildup of my firebird, now that the thing is finally paid off i can get started on some serious mods. my plans so far are to get:

pacesetter long tubes with ORY and a random technology cat-back

McLeod street twin w/steel flywheel and adjustable master cylinder

LPE 3.5" aluminum driveshaft

eaton posi with GM/Motive 4.11 gears, rear end girdle, and hardened axles for the stock 10 bolt.

spohn crossmember mount torque arm and adjustable rear lower control arms


my question is this, do you guys think that the rear end will hold up to the street twin after those mods? i also plan to get a cam later in the summer, hopefully i can afford a custom setup from brett bauer. can anyone give me a price range on a cam/valvetrain package from him? how well do you guys think the rear will hold up to 350HP with those upgrades? i'll be ordering the parts in about 2 weeks so that they arrive when school lets out for the semester and just wanted to see how well this all would work together. maybe someone is running a combo out there similar to what i'm trying to put together here.

 

Does your car have an aluminum DS already? If so just stick with that. No need to buy a stronger one unless you have big hp numbers.

Headers are an opinion matter. I like the Jet Hot Lt's myself. They are pretty cheap with the best coating.

Same thing with the catback. I have borla and love it.

Why an adjustable master cylinder? The clutch and flywheel looks good.

Don't waste any money on the rear end. You will end up buying a 9" or 12 bolt anyways. There is not enough you can do to a 7.5" rear that will make it strong enough to handel any kind of power. It is like putting a bicycle chain on a drag bike. I don't care if it was made of titanium it just wouldn't hold up.

 

my car is stock except the CAI and the shifter. the master cylinder has a small leak i think,i hear gurgling noises coming from it every now and then. besides it comes with the street twin i thought? and this all has to be done on a budget. the exhaust is pretty inexpensive, coated pacesetters and ORY are about as much as the hookers without the Y-Pipe. i'm putting that money into the rear in hopes that it will last me to next december, since i wont be able to afford a 12bolt this summer.

 

i have no idea if it comes with a street twin. I have a centerforce dual friction. I have never heard of a clutch kit coming with a master cylinder but i could be wrong. Look under your car and see if the drive shaft is gray or brown. Gray is an aluminum and brown is a rusty steel. Get the parts your budget can handle but don't substitute price for bad quality because you will end up spending the money for the better parts after the other ones break. I'm not saying anything you have listed is bad quality, i'm just giving you general knowledge. My car has been down for a year now because i'm holding out for better parts. Sure I could have thrown it back together months ago but i want a better build.

 

Well, I have noticed one thing for sure since coming on this site many moons ago: we all spend our time and money on the front end increasing the HP and TQ only to wind up wishing we would have seriously considered how we were going to put that much power to the ground (i.e., if we planned on doing a few hard launches).

Everyone here knows that the 7.5 gears that GM (stupidly) provided as OEM on their muscle cars just can't handle much abuse and yet we (as in I) talk about how to beef up the clutch, DS, etc. knowing full well that it is the rear end that is going to give first.

Having said this about that, I would recommend that one consider swapping out the 10 bolt for a good 12 bolt while you have the do re me rather than nickle and diming bolt ons.

It is really hard to consider putting a couple of grand+ into the 12 bolt after you've put all your change in the powerplant, so why not get it out of the way if that is the type of driving you intend to do.

I sure wish I had a 12 bolt.

 

hrmm, i guess you guys arent understanding me. i'm not trying for a 400hp monster here, i'm going for a mild bolt on LT1 with about 350 flywheel HP. i'm trying to beef up the suspension and drivetrain as much as possible before i dig into the motor. a 12 bolt will cost me as much as all these mods put together, and i need to do these mods anyways. clutch is from autozone and is on its way out, master cylinder is leaking a bit i think, u-joints are about gone, and cats are clogged. so i would be spending a grand at least just replacing those parts this summer, wich would rule out a 12 bolt anyways, i just thought that i might as well replace all that stuff with performance parts.

if you'll look at the mods i'm putting on, the only HP increasing item is the exhaust system, everything else is in the drivetrain behind the engine.

as much as i wish i could put a cam and valvetrain package on my car, it wouldnt be done until either later in the summer, or in december. i simply cant afford to put 6k into my car atm.

 

if you have an aluminum drive shaft already then just have the u-joints replaced. Way cheaper and it is a very strong driveshaft. You can save some money right there. In your original post you said you wanted to buy an eaton posi with GM/Motive 4.11 gears, rear end girdle, and hardened axles for the stock 10 bolt. I am telling you that this is also a waste of money. Focus what money you plan on spending in other areas. Suspension mods are always good: torque arm, trailing arms, panhard rod, springs, and ect...I would just hate to see you dump all that hard earned cash into the rear end that is going to break no matter what you do.

 

i have the stock steel driveshaft with original u-joints. so you guys dont think that with the upgraded parts in the rear end that it will last 6 months behind the street twin and stock internals engine?

 

Stay away from Drag Radials till you do move up to a 9" or 12 bolt

 

Dont waste your money on upgrading the stock rear. With your mods it may even last a while. If you plan on taking it to the track often and if you are going to run slicks or dr then you are going to want to upgrade it. If not, leave it the way it is. Then if and when it does break you havent wasted your money on it and will have more money towards a 12 bolt.

edit: I've been running stock rear on the street now for the two years that my car has been a 383, with no problems as of yet.

 

My stock rear holds up nicely to drag radial abuse (I do have an automatic), I know several people that were running mid 10's on their stock 10 bolts. I dont think that you will have any problem with the 10 bolt and your setup for a while. I wouldnt spend the money on the rear because I really dont think that you will need it till you start doing internal modding. If you are sensible with it will last.

 

thanks for the info guys. guess i wont be spending that money on the posi unit and axles. i will however get the rear stud girdle and the 4:11 gears. does anyone have any opinions on the solid pinion crush sleeves?

 

no opinion on the crush sleeves but the 4:11 gears will increase the chance of a destroyed 10 bolt. I would stick with the plain jane stock 10 bolt until you break it. There are a handfull of amazingly strong 10 bolts out there. I have one of them. I have dumped the clutch from 4500 rpm's with 26x11.5 ET Streets pulling consistent 1.7 60' times with not even a cry for help from the rear. I know it is only a matter of time though.