I have been debating the same question for my 00' vert 6spd. 3.90 are the gears of choice by 90% of the locals that I have spoken with. I wish I could change mine out now but my car is stuck in my father-in-laws garage, to much snow blocking the garage door.

 

Your question has no point. To what end or purpose is the gearing change to accomplish? Is this a street or road track or 1/4 mile? Are there any other considerations you have?

None of my cars are DD. MPG means nothing particular to me. The 2000 FRC is OEM 3:42 and the wife rarely shifts to 6th gear. My Z06 M12 is gear differently compared to the FRCes MN6. The installation of 3:90 was a good street compromize particulary with the tire wheel combination 305/35-19 rears I have now. The gear change for me was a 11% change but with the larger (taller than OEM )tires its more like a 5 % change.


So consider what tire combination in your equation. Gearing is just as important as horsepower. Wrong gearing for the application or purpose can kill the performance .

 

i daily drive my z06 with 4.11's and have no problems. now i actually use 6th in the city

 

Deff want a cam and heads in the future prob England Green whiplash2 cam and some nice heads

 

I have 3.90 ... love them. Not bad on highway ... great on strip

 

[QUOTE=lomoman;1573155631]I have 3.90 ... love them. Not bad on highway ... great on strip[/QUOTE

hey were li u from, btw what mods do you have done to your vette

 

I have 3.90s (along with some other mods ); luv the kick out of the corners on road courses with these gears! And, they're not bad for highway use.

The stock 3.42s are good all-around, esp. for daily driving.

Go with 4.10s if your beast will be mostly seen on a drag strip.

Have fun!

 

Check out ECS RPM vs Gear vs Speed chart. I have a 01 6 spd coupe with 347 rwhp. I started out with 3:42's and hated them. I went to 4:10's and had a riot. Tires went fast. Forget about "1st" and 2nd gear traction, but a lot of fun. Now 3:90's and very happy with the gear vs speed range. Not as much fun but it will be perfict when I get done with the SC. Make sure to raise your rev limiter also.

 

yea that was helpful 2 cents what would you set the rev limiter too with 3.90s prob gonna get a mail order tune

 

Leave your rev limiter stock with your factory valvesprings.

If you had ls6 or comp918 springs I'd say 6300 is max with your stock cam. With a hotter cam they nose over around 64-500... So the limiter is around 6800.

Rule of thumb, your redline is 300 rpm past where the cam noses over.

 

thanks good to know, leaning towards 3.90

 

4.10s for H/C application...it also matches the gear ratio of the MN6 perfectly! I have no traction problems in first or 2nd because i relearned how to apply the throttle and let the gears work for me

 

i have a cam only car with 4:10's. 1st gear is all smoke. 2nd gear will hook intially til about 4500 rpm then smoke to red line. 3rd-6th are good. Lots of fun but if i did it agin i would go with 3:90's.

 

I've got a mild 402/L92 combo and I love my 4:10's! They make 6th gear usable.

Bob K.

 

Okay, 3.90's or 4.10's sound great for those with MN6's. I'd like to hear more from those who are running MN12's....

Sorry about the hijack....

 

Buy his brand new 315 gears differential and he will upgrade it to 4.10 or 3.90, he does pro job check his past threads.

Or upgrade yours by him.

 

My rev limiter is safely set at 6600 rpm. Any setting above that should have better springs, which is what goes on next.
HP peaks at about 5300 and held thru 6800 when dyno was shut down. Did NOT nose over.

 

500rwhp on a 6mn and 1st is already too short.

 

If I were getting gears I'd get the 3.90s. My rev limiter is stock so I probably running into it a good bit. With an extra 500-1000rpm, I wouldn't have a problem getting 4.10s.

I hate the 3.42 gears. Hate.

 

Keep the 3:42's or if your hell bent on changing no more than 3:73's! Anything more with good power is a waste!