another H/C question!

[Faught]

sup guys i could not find the answer to my question using the search so here it goes, im looking at a H/C upgrade for my DD 99 t/a but i'm unsure what to do mainly b/c of my budget of $3500 for install and all(i would do it myself but i no longer have the proper tools ) i have a mechanic who can install and tune for $1450 so that leaves me $2050 for the rest(oil pump, timing chain, trunnion upgrade, h/c, all gaskets, bolts, push rods, and fluids)
for the heads i was thinking of,
port polish stock ls1 heads
pick up some used or new 243's
PRC 2.5 ls6
and im not sure what cam i want, it needs to be streetable and not rob gas mileage but i would like a nice bump in power, i will have a yank 3K converter and tranny cooler. my goal is to have a low 12 sec street car.
plz help

[Firebirdjones]

Low 12's is an easy goal. With bolt on's, a converter, sticky tires, some gear, and the car will run mid 12's without even getting inside the motor.

From there, just a cam alone will get you low 12's easily, and more than likely 11's. No need for heads with your goal...but if you wish.

With only $2,000 left over after install labor spent,,,about half that will be eatin by the camshaft and necessary parts alone. That isn't leaving you much for heads. Along with heads comes other expenses that you listed like the gaskets and bolts. You might pull it off but it would be squeaky tight.

[Faught]

ya ive bin talking with my mechanic and it would run me right at $4,400 for everything. I guess for right now ill get my converter, tranny cooler, and a TA 10 bolt cover, i'd like to beef up my 10 bolt a little lol, and while on that subject have any suggestions on gear oil for when i replace the cover?

[Firebirdjones]

You'll like the converter, that's the best upgrade for an auto LS1 you can do. From there I'd just do the camshaft, a good tune,,,and forget about the heads for now. I'll bet the car will go faster than your original goals.

As for gear oil, pick your favorite name brand and use 80w-90. Pennzoil, valvoline, Amsoil, etc.. What ever you prefer.

[NeeD4SpeeD]

ya ive bin talking with my mechanic and it would run me right at $4,400 for everything. I guess for right now ill get my converter, tranny cooler, and a TA 10 bolt cover, i'd like to beef up my 10 bolt a little lol, and while on that subject have any suggestions on gear oil for when i replace the cover?

From what i hear and understand, the TA 10-Bolt cover is a waste of money and really doesn't do anything to strenthen your rear all that much. I would take the $1xx.xx or however much it is and put it toward some nice tires Just my .02 To each his own!! Good luck with your build!!!!

[1nasty86]

there is a bullet proof 10 bolt build on ls1tech that has braces from the diff cover to the axle tubes. what breaks a 10 bolt is the rearend actually flexing and throwing the pinnion off and causes the gears to break.

on another note..... id get a set of used 243's and since it is your d/d thrown in a ls6 camshaft, ls7 lifters, ls6 pump and a ls2 timing chain. DONE!

[Firebirdjones]

Tube braces are meant to keep the tubes from bending towards the front of the car on very hard launches.
It's generally only necessary on serious "track only" cars that are running sub 1.5 60 foot times, heavy cars with a serious shock load.
It's overkill for even a stout street car that sees limited track duty. To put one on a 7.5 inch 10 bolt is a waste of time. Putting a 7.5 through that kind of track abuse,,,the axle tube deflection would be the least of my worries.

The diff covers made by T/A and various other copies now, are meant to simply pre-load the bearing caps and minimize deflection. This contrary to tube braces, is a very worth while mod even for a mild car.
As power is applied, the pinion gear tries to climb the ring gear. This pushes the ring gear out towards the back of the housing, and cast iron bearing caps tend to deflect, and in turn you get very odd ring gear wear patterns. In severe cases the cast iron caps will break. The pre-load from the T/A covers prevent this from happening and you end up getting better/longer gear life with better wear.
You can also run billet steel caps to prevent this, but the housing has to be re-honed to ensure proper bearing crush.

What really kills these 7.5 inch 10 bolts is their inherant design flaw. When you only have a 7.5 inch ring gear diameter, you have less gear contact between the ring and pinion. When you install more rear gear (which most everyone does) You decrease that contact pattern. This in turn weakens the rearend further.

For instance, if you install a 4.10 gear,,,you will only have 1.5 teeth of contact at any given time. This is why you will see sheered teeth off the ring gear. Even a 3.73 gear only has 2 teeth contacting at any given time. It's not that much better. Remember the more gear you install, the smaller the pinion gear gets.
It's pretty easy to tear up the ring gears in these cars, I've also broken axles, and destroyed the weak style posi units. In one case I even snapped the pinion gear in half.
If you want a rearend with more gear, you are better off going with a larger ring gear diameter like a 12 bolt (8.875 dia.) or a 9 inch,,,to keep a higher tooth count contact patch for strength.

[1nasty86]

Sorry for the misinformation.

[Firebirdjones]

No need to appologize. I just hate to see people spend money on things that aren't absolutely necessary. So I threw some info out there that I hope can be helpfull to someone. It's all good.

[SSwt00SS]

I would believe you could obtain your low 12 sec e/t goals by induction, intake, full exhaust, cam, a stall, and a killer tune. that should also keep you in your price range of $3500.