I was researching the conversion from auto to manual and was going to install the Tremec 5spd, but when I contacted a shop from Classic Chevy 5 Speed who was a certified installer, he told me that with a 4.11 rear I may be shifting out of overdrive a lot. He suggested the T-56. I was wondering if anyone has run into this issue? Does anyone out there have a 4.11 rear and had the 5spd installed without any issues? Thanks.
5 Speed vs. 6 Speed
67CamaroRS/SS
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I was researching the conversion from auto to manual and was going to install the Tremec 5spd, but when I contacted a shop from Classic Chevy 5 Speed who was a certified installer, he told me that with a 4.11 rear I may be shifting out of overdrive a lot. He suggested the T-56. I was wondering if anyone has run into this issue? Does anyone out there have a 4.11 rear and had the 5spd installed without any issues? Thanks.
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I'm not quite sure what shifting out of overdrive a lot means. My cousin is running a T-5 with 4.10 gears with a 302. The T-5 has the same overdrive gear as the Tremec, .68 I belive. He does not have this problem he puts the car in overdrive and heads down the highway. I would say you would have a bigger issue of shifting out of overdrive with a higher gear such as 3.08.
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I believe there is also an issue with the low gear gearing. With the Tremec having such a low first gear it would be like having a granny gear. Almost useless. He said I would have to shift pratically immediately. How is your cousins' first gear? Is it a quick shift to second? I was preferring the Tremec, but the driveability of the Tremec sounds like it isn't going to work with my rear.
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Note that there are 2 tko 5 speeds. with the tko500, and it's 3.27 first, that would be a big issue with a 4.11, the tko 600, and it's 2.83 first is not so big an issue. This is also about the same ratio as the T56.
The T56's .5:1 high drops the r's a TON. Same like I get with a .64 tko and a 3.08 gear, right around 2:1 overall. This will put your highway rpm's at about 2000 @ 65.
With the tko, your highway rpm's would be more like 2500 @ 65.
Either the tko600 or the t56 would work well with your 4.11 gear.
The T56's .5:1 high drops the r's a TON. Same like I get with a .64 tko and a 3.08 gear, right around 2:1 overall. This will put your highway rpm's at about 2000 @ 65.
With the tko, your highway rpm's would be more like 2500 @ 65.
Either the tko600 or the t56 would work well with your 4.11 gear.
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I currently run a 2.66:1 first gear T56 and 4.11 rear gears and love them. (I like them so much I've ordered 4.11's for the rear in the car I'm currently building, which will also have a 2.66:1 T56.) Before I installed the 2.66:1 T56, I had an Aftermarket T56 with a 2.97:1 first gear in the car. That was not so good. First gear was short and 6th still was rev'ing more on the freeway than I liked.
A 2.83:1 first gear is about midway between the two T56's I had in my car, so your first gear will still be a little short. What I'd be concerned about though is 5th gear. With my 2.66:1 first gear T56 and 4.11's, I'm turning about 2,000 rpm at 75mph (0.50:1 6th gear). With a 2.83:1 first gear and 4.11's, you'd be turning about 2,500 rpm at 75mph (0.64:1 5th gear). That's a big difference.
If you're set on the 4.11's, I'd go T56. If you're willing to change the rear gears, the TKO should be fine.
A 2.83:1 first gear is about midway between the two T56's I had in my car, so your first gear will still be a little short. What I'd be concerned about though is 5th gear. With my 2.66:1 first gear T56 and 4.11's, I'm turning about 2,000 rpm at 75mph (0.50:1 6th gear). With a 2.83:1 first gear and 4.11's, you'd be turning about 2,500 rpm at 75mph (0.64:1 5th gear). That's a big difference.
If you're set on the 4.11's, I'd go T56. If you're willing to change the rear gears, the TKO should be fine.
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Ok. Thanks guys.
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I have a different situation so take it with a grain of salt.
582 BBC 4L80E tranny with a 2.48:1 first gear and a 4.56:1 rear end. I spend a total of 1.41 seconds in first gear on a hard launch with a 3,600 RPM converter, according to my data recorder. What I like about my electronic controlled automatic tranny is how fast (and consistently) it can shift. Cruises at 3,000 RPM (70 MPH) with my converter locked up and 28" tall tires.
Only mentioned it because of question about short shifting first.
Larger Dave
582 BBC 4L80E tranny with a 2.48:1 first gear and a 4.56:1 rear end. I spend a total of 1.41 seconds in first gear on a hard launch with a 3,600 RPM converter, according to my data recorder. What I like about my electronic controlled automatic tranny is how fast (and consistently) it can shift. Cruises at 3,000 RPM (70 MPH) with my converter locked up and 28" tall tires.
Only mentioned it because of question about short shifting first.
Larger Dave
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LOL, I know what you mean. When I brought the '68 I'm working on now home years ago, it was screaming at about 3,500 rpm at 70mph. In that moment, I realized that OD transmissions were the only way to go.
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+1 what JimM posted. Actually the .64 od with a 4.11 rear gear is a pretty sweet combo.:thumbsup:
Richard
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Here are some realistic Ratio's
Tko 500 3.27 1st final is a.68 4.11@2200 rpm 61 mph
Tko 600 2.87 1st final is a .64 4.11@2200 rpm 65 mph
T56 with a .50 4.11@2200 rpm is 5th 56mph 6th is 83 mph
Tremec makes both of these transmissions
Keep in mind with the 6 speed the .50 od at normal hwy speed is only going to run about 1700-1800 rpms most carburated motors are not going to run well there,especially under load. You would shift more with it then any others.
Gene
Tko 500 3.27 1st final is a.68 4.11@2200 rpm 61 mph
Tko 600 2.87 1st final is a .64 4.11@2200 rpm 65 mph
T56 with a .50 4.11@2200 rpm is 5th 56mph 6th is 83 mph
Tremec makes both of these transmissions
Keep in mind with the 6 speed the .50 od at normal hwy speed is only going to run about 1700-1800 rpms most carburated motors are not going to run well there,especially under load. You would shift more with it then any others.
Gene
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1,435 Posts
not true. In a Vortech-blown 4th gen with T56 and 4.10's you'll start making boost around 110mph in 6th gear.
I'm running the 2.66-first T56 with 3.73's ans 27" tire in my '68 and love it! I rarely use 6th right now though--speed of traffic on GA400 varies between 60-90mph on daily my commute. That's 2000-3100 RPM for my in 5th, and the LS1 is pretty happy in that RPM range. I'll probably use 6th a bit more after install a cruise control module. At least it's better than my '00 Rustang daily driver--with a T45 and 3.20 gear, I almost never use 5th gear in it unless I'm on a road trip.
Here's a calculator I found on Google with 4th gen T56 ratios already typed in: http://www.xse.com/leres/ss/calculator.html
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I plan to put the Keisler's T56 in my car, when I can scape up a little more cash. I believe it will really tame down my 4:56 rear gears with the .74 and .50 overdrive gears.
http://www.keislerauto.com/gm/transmissions/camaro_67-69_6spd.asp
http://www.keislerauto.com/gm/transmissions/camaro_67-69_6spd.asp
I recently converted from 700R4 to TKO600 w/.64 OD gear. (best money I ever spent - different animal now) I have 373 gears in rear. This combo works excellent for hi-way and also having fun accelerating fast. Your 411's put you in an area where the TKO600 may be a little less than ideal on the hiway (if your going to be doing this type of driving for long periods of time) Where I live we have 75mph speed limits on most hiways and would not want RPMs as high for gas and comfort and engine wear & tear that 411s would ride at. If your into hiway cruising for long periods I would either do the 6spd. or consider doing the 5spd. (TKO600 w/.64) and changing to 373s which would still be a little less $ and first gear would not be so low. Really depends on what driving your going to do but would not recommend the 411s for longterm hi-way riding at 75+mph - it can be done but not ideal. Since you're going to spend lots of money on this conversion you should make sure you do it right the first time.
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I have decided to go with the t-56, but now I have to decide on which t-56. Aftermarket, Viper, Mustang, Corvette. So many to choose.
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