3.90 vs 4.10
10-13-2007, 04:04 PM
#1
Instructor
Thread Starter
3.90 vs 4.10
I have 3.55s in my differential right now. Im thinking of bumping to 3.90s or 4.10s. How much of a bottom end difference is the jump? I dont think I'll be able to tell a difference if I go with 3.70s.
10-13-2007, 04:09 PM
#2
Le Mans Master
Are you going aftermarket? Neither 3.90s nor 4.10s are GM Corvette gears. GM Corvette gears jump from 3.70s to 4.11s.
10-13-2007, 04:12 PM
#3
Instructor
Thread Starter
I am going aftermarket. Not a lot of companys make 3.90s but I figured it would be more streetable than 4.10/ 4.11. Not really sure about it so thats why I asked.
10-13-2007, 04:24 PM
#9
Melting Slicks
Member Since: Mar 2007
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My '69 427/435 has factory 4.11 gears (and an L88 cam)...I call the car "Stumpy" because it could pull tree stumps. It really doesn't even need 1st and 2nd gears.
If you like turning lots of rpm's at moderate speeds and single-digit fuel mileage, go for it. I get maybe 6mpg and about 125 miles to a tank of gas.
If you like turning lots of rpm's at moderate speeds and single-digit fuel mileage, go for it. I get maybe 6mpg and about 125 miles to a tank of gas.
10-13-2007, 05:40 PM
#14
Team Owner
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St. Jude Donor '05
Dont..If you really want acceleration get the 4.10. Anything over a 3.40 gear and your crusing rpm will climb up there anyway, so go for the gusto.
If you dont have one, get a 700R too, and have the best of both worlds.
I went from 3.08 to 3.73 to "split the difference" (this was in another car I have)..Bad move.
A week later I was in the shop getting 4.11s and did an overdrive conversion, best thing I ever did.
If you dont have one, get a 700R too, and have the best of both worlds.
I went from 3.08 to 3.73 to "split the difference" (this was in another car I have)..Bad move.
A week later I was in the shop getting 4.11s and did an overdrive conversion, best thing I ever did.
10-13-2007, 06:45 PM
#16
Heel & Toe
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10-13-2007, 06:47 PM
#17
Instructor
Thread Starter
A week later I was in the shop getting 4.11s and did an overdrive conversion, best thing I ever did.[/QUOTE]
Ive repurchased many different parts because I didnt like the way they've performed like radiators, water pumps, fans, intakes, carbs,heads, ect. the list goes on and on. Sometime down the road I'll be looking at a 2004r con. So why not 4.11s, thanks
Ive repurchased many different parts because I didnt like the way they've performed like radiators, water pumps, fans, intakes, carbs,heads, ect. the list goes on and on. Sometime down the road I'll be looking at a 2004r con. So why not 4.11s, thanks
10-13-2007, 07:28 PM
#19
Le Mans Master
I changed my 4.11s to 3.70s. 4.11s are fun, but without an OD, you'll turn about 3,600-3,800 RPM in the slow lane just trying to keep up with the ricers on the freeway. 3.70s reduced this to about 3,200-3,400 RPM.
I found that 3,800 RPM = lots of vibration, noise, and lousy gas mileage.
Eventually I put a TKO-600 in so, the 4.11s would have been OK. But consider that compared to the Muncie, 1st on the TKO is equivelent to going to a ~3.90 rear gear in 1st.
I found that 3,800 RPM = lots of vibration, noise, and lousy gas mileage.
Eventually I put a TKO-600 in so, the 4.11s would have been OK. But consider that compared to the Muncie, 1st on the TKO is equivelent to going to a ~3.90 rear gear in 1st.