4:10's & 3:90's Pros and Cons

[Scott97]

Looking for first hand experience with the 3:90 and 4:10 gearsets.
Any racers breaking them, other problems?

Thanks!

[Mongoose400SS]

I have had experience with 4.10's in a 99 Pewter FRC that turns 11.80 at 117 with all bolt-on's and polished heads I like them but on the drag strip it uses all of 4th and first time out thought I was going to power shift 5th!! If we had it to do over I would rather install the 3.90's.

[ZO6LS6]

Scott,
With those #'s, I would not be surprised at some output shaft problems.........even with F1's.......
A few guy's I have seen on the forums LOVE the 3.90's.......
3.73's seem to be not enough difference, and 4.10's are too much....
But, to each their own...
Me, I think 3.90's on a stock., or CLOSE to stocker would be THE way to go...for strip use, and street..........

[RandyN]

They have been great for me. Car has great snap in 1-2-3. Fun to drive and now pulls in 6th. I chased down a 1000cc bike two fridays ago in I-75 going south. After the curb at Miramar parkway it is straight for 2-3 miles. My speedo read 173. Now remember my speedo is 13 MPH off at the track. I trap 117-118 and the hud reads 104-105. We raced from 100 mph and there was two bikes. The 600 was not a player after 150. We were going so fast I had to go to Miami lakes to turn around to go back North to Davie. On the way back I joined a race between a Black vette and an M3. No contest. Then they signaled me to race a blue 99' camaro. It had a super charger and pulled me in 3 rd and 4th. One length in 3rd and two in 4th. That was a lot of action for about a 20 minute ride. I will be installing the fastech F1 cam next week. Purchased today from speedtek. To bad I don't live by them as they are running a great special on install. Also going on will be a pulley, Line lock, tell tale tach, and a 175 shot of spray.

Randy

[Scott97]

Originally posted by Mongoose400SS
I have had experience with 4.10's in a 99 Pewter FRC that turns 11.80 at 117 with all bolt-on's and polished heads I like them but on the drag strip it uses all of 4th and first time out thought I was going to power shift 5th!! If we had it to do over I would rather install the 3.90's.

Thanks for the input.
Did you raise your rev limiter or was it still @ the factory setting?

Originally posted by ZO6LS6
Scott,
With those #'s, I would not be surprised at some output shaft problems.........even with F1's.......
A few guy's I have seen on the forums LOVE the 3.90's.......
3.73's seem to be not enough difference, and 4.10's are too much....
But, to each their own...
Me, I think 3.90's on a stock., or CLOSE to stocker would be THE way to go...for strip use, and street..........

Thanks for the reply.
I've been polling a few different forums and the guys with the 4:10's are very happy for the most part..
I plan to install hardened output shafts as well.
I agree on running the 3:90's on a stocker setup.
It would make an enormous difference.

Originally posted by RandyN
They have been great for me. Car has great snap in 1-2-3. Fun to drive and now pulls in 6th. I chased down a 1000cc bike two fridays ago in I-75 going south. After the curb at Miramar parkway it is straight for 2-3 miles. My speedo read 173. Now remember my speedo is 13 MPH off at the track. I trap 117-118 and the hud reads 104-105. We raced from 100 mph and there was two bikes. The 600 was not a player after 150. We were going so fast I had to go to Miami lakes to turn around to go back North to Davie. On the way back I joined a race between a Black vette and an M3. No contest. Then they signaled me to race a blue 99' camaro. It had a super charger and pulled me in 3 rd and 4th. One length in 3rd and two in 4th. That was a lot of action for about a 20 minute ride. I will be installing the fastech F1 cam next week. Purchased today from speedtek. To bad I don't live by them as they are running a great special on install. Also going on will be a pulley, Line lock, tell tale tach, and a 175 shot of spray.

Randy

Thanks Randy.
Sounds likre you really like the 3:90's.