Hi all, I have a 1996 Corvette with the LT4. Im aware the car is stock with 3.45 gears and was wondering if 4.10s would be a good choice for me? As of right now, I have never taken the car to the strip and this would be used as more of a street application. Im aware of the tradeoffs being that I would get alot more low end grunt which is what I love but my top end would suffer. I dont know much about gears and Im trying to read up and collect input. What do you guys think? I figured if Im going to race, you can only race short distances so 4.10s might be a good upgrade for me. Pros and Cons? as well as estimated price range for parts and install. I keep reading that 4.10s are great but want to get some input on whether this should be something I should look into. All helpful comments welcome.Thanks!

 

Love the 4.10's in my 94 M6 LT1, have been running them for ~15 years without issue. 1800 rpms in sixth gear at 70 mph, and has trapped 119 mph in the 1/4 mile. How can I complain!

 

4.10s are perfect. Add hotcam youre in heaven

 

When you trapped at 119mph what was your ET?

 

^^^ 12.37/1.9x 60', was running street tires.

 

If by "top end" you mean top speed, you won't need to worry about that. As it sits stock, your car is probably slower in 6th gear than in 5th. Even with 4.10s, you'll have plenty of gear for whatever high speed you want to achieve. The ZF6 has fairly tall 1st and 2nd gears, so it would feel nice with 4.10 gears in the diff.

As for the best ratio for "racing," it depends on what kind of racing and what class within that type of racing you plan to do. It also matter what other mods you plan for the future. If it's just drag racing we're talking about, then the ideal ratio is the one that lets you get very close to redline in the finish lights. For a stock-motored LT4 on stock tire diameter (25.6" or 26.1"), 4.10s are good but 4.33s are better, and 4.56s may be just right. But these steeper ratios will be a little extreme for the street. For road racing you need to plan for the tracks you plan to visit. For autocrossing, you want the ratio that lets you stay in 2nd for most courses, and 4.10s is probably the very upper limit for that in a stock LT4 car (for a 396 with heads and cam it would be too steep - I'd be hitting the rev limiter a lot, because I'd be maxed out at 66mph). Finally, you need to look at the rules for the class(es) you plan to race in. Gears will get you bumped out of a lot stock-rules classes. If you're just talking about stoplight racing and run-what-ya-brung nights at the local strip, then it's no problem.

 

4:10 is a great gear for the ZF. Ran them in my GS for years when stock cube. First mod I did to my ZR-1.

 

Thanks for the input guys. Although 410s sound great seems abit aggressive and because i do drive the car often and how tempting it is to step on it...my fuel economy might go down even more. I will think about it. I mean Im just brainstorming as of now. What do you guys think of 373s? A bump over the stock gearing seems like a good middle of road. Current mods are SLP CAI (Cut lid for smog) , Borla Catback, Pacesetter Armor coated Shorty Headers (because I live in CA), MSD Coil, Dimpled/Slotted Rotors,TB Bypass. Car is pretty mild and future mods aside from upgrading gear would be heads/manifold porting, maybe x-pipe if possible and cams in the extreme future or if rebuild comes first. I do need a tune to get the most and the mods on the car could benefit from that.

 

I went with 3:73 and love them for street driving great use of all the gears also pushing 500chp . I also tried 4:10s just not my cup of tea, I do not run the quarter mile.

 

YES on the 3.73 - here in the WV 'twisties' I thought 3.73 might be ideal.

Do the math for 3.73 - 3.90 and 4.10, The 3.90 never gets much conversation but I believe it would make many very happy. I have a set of 4.10 and 3.73 'NIB' I might be selling. I actually also have a set of 3.54 NOS GM still too. I had some 3.90s that before I had a chance to install a local fellow was looking to do an engine break in. I let him use my 3.90 'set-up' and he later bought.

The 3.90 was actually an older D44 -STD with bearing sleeves in the Corvette housing. Will goes by 'rklessdriver' here on the CF

 

93 STOCK LT-1 / A4 tranny. Looking for a fun street to strip, "run what you brung" car. Dana 36. I like the idea of 3:90s or 4:10s but what would my RPMs be at 75mph in OD?
will they fit the Dana36?
fuel consumption not considered
thanks for your opinion.

 

Don't fear the gear. As you ask around about this, I want you to notice that nobody ever post how they feel they went to low (Higher Numerically). The only top end you will lose will be your mph. As a street car, are you really worried about Top Speed or how fast you can get there. Most street driving will be between 30-90mph and acceleration between those speeds.

At any given RPM, a higher numerical gear will multiply the engine torque to the wheels more than a lower numerical gear. It is the same as adding more torque to the engine. Remember, HP is just a calculation based off torque. You do not lose anything the engine is capable of producing by changing a gear.

Where too much gear can hurt is:
1. It causes you to add another shift in a 1/4 mile that you didn't have before, but the added acceleration doesn't compensate for the brief moment of non acceleration during the shift.
2. You don't have enough gears to shift into and you hit your rev limiter before reaching the traps. This will hurt mph more than ET to some extent. Watch top fuel guys who have to lift mid track. They will turn in a trap of 125mph instead of 315, but their ET drops from a 3.60 to 5seconds because of how fast they accelerated/covered the first 1000ft.
4. Your RPM Range will not support the combination of rear gear/transmission gear and you don't get enough use out of your RPM Range to accelerate. Like a TPI that would like to shift at 4800 RPM... then what does it drop to? Gear Spread in the transmission matters. If you shift at 4800 RPM and drop down to 2500 and only can go to 4800... well you will be out of usable RPM and only using 2300 RPM window to accelerate in. Where as an engine that can run to 6500RPM and will shift down to 3500 RPM would have 700 more RPM to use with the same gearing combo.
5. Traction.

This is why a TPI with stock runners does not like to run much more than a 3.42 gear... 3.73 at an absolute max. An LTx motor with a auto is going to like the 3.73 and a stick will run well with a 4.10... if you can maintain traction. I have a blower on mine, so a gear change isn't in my plans due to traction. Otherwise I would be putting a 4.10 in no question. Had one in my 4.6L SN197 Mustang and loved it. Had a 3.55 in my Viper and loved it. Don't fear the gear!