RED92BIRD305

would a 4.11 rear end gear be too much for my mostly stock LO3 i am ordering my parts for the rear end rebuild and didnt know what gear to go with i am looking toward a 4.11 4.10.

dimented24x7

iTrader: (2)

anything above 3.73's will be too much gearing for a stock 3rd gen. It might even hurt more then help. IMHO id use either 3.42's or 3.73's. Had 3.42's in a tpi and they where a pretty good match to the low revving L98.

25THRSS

given that a stock L03 f body will trap low to mid 80's, and you want to cross the traps just after your peak hp, 4.10 would be a great gear for STOCK. If you plan on trapping higher it will be too much gear. I got 3.42's because I plan on trapping very high in the near future and this is the optimum ratio for me. First decide where you will be trapping then you can pick the set of gears to match your car.

dimented24x7

iTrader: (2)

In D at 4k the trap speed would be around 70 something mph with 4.10's with stock sized tires. It would be ok at the track but youd ahve to shift into OD when youd be nearing in on the traps with the stock L03. Also, with 4.10's itll be a pain if you have to do any driving on streets with speed limits above 50. Youll have to spin it up pretty good to get to highway speeds. Also, with the L03's narrow powerband your trans' shifts will be closer spaced so if its a slow shifter itll cost time since the trans will take time shifting rather then allowing the car to continue accelerating. Also keep in mind that the stock converter has pretty good torque multiplication and combined with the 3.08 first gear you may have traction problems in first. There are also possible issues with rotating inertia eating power and so on but if its a track only car that will see mods in the future then the 4.10's are a good investment but if you have to drive it a bit then they might not be such a good idea.

25THRSS

Why in the world would you want to shift at 4000 anyways even on a stock l03? I gained a full half second shifting at 5,000 rather than the stock 4400. stock I trapped a little above 82 mph. Even if you trapped 85 you would only be at about 4600 rpm which leavs you a tad bit of room to work with, but not much. I agree that if you plan on doing any other mods that will increase your trap speed i wouldnt go with 4.10's. I'de stock with 3.73's, but if you are wanting to know what gear ratio would be best for an otherwise stock l03 4.10's would have to be it. Please remember people that the ONLY way to choose the correct gear is to take your trap speed and tire size into account and then go from there. There is no real "best gear" for our cars. Each is different, and you just have to do a few plans and calculations to find out what will be best for you.

RED92BIRD305

i am planning on doing alot of other mods but i will be driving the car on the street and every year i have a 300 mile drive to the t/a nats

dimented24x7

iTrader: (2)

It was an off the cuff response... Not really taking into account carrying the gear past the peak horsepower to optimize the use of the powerband in the next gear. My bad...

If you plan on lots of mods but still have to do a fair ammount driving its probably a better bet to stick with 3.73's, or 3.42's. To me, theres more to gears then just trapspeed. The whole car really has to match the gear and vice-versa. Just like any other part. Low gear ratios mean that the rotating mass that consitutes the rotating assy and the inner components of the trans will have to accelerate faster and will consume more power in the process. There is also the transmissions shift speed to consider since its shifts will be more closely spaced with the lower gear ratio. This topic has come up alot in the form of '4.10's with my LG4?' and so forth and its pretty hotly debated in those threads as well. This is my take on it, and Im sure others will differ, and thats ok, but its up to you to decide how much you want to compromise drivability, fuel economy, performance etc. with your performance mods. Me personally, after my experences with my ultra-torque no horsepower 350 Id never run a low gear on any motor resembling that ones powerband. Even with 2.77's and posi (works about 70% of the time), traction on the street is a nightmare even on pricey performance tires. I