C3 Tech/Performance V8 Technical Info, Internal Engine, External Engine, Basic Tech and Maintenance for the C3 Corvette
Sponsored by:
Sponsored by:

Transmission upgrade?

Thread Tools
 
Search this Thread
 
Old Sep 6, 2015 | 01:15 PM
  #1  
084273lz's Avatar
084273lz
Thread Starter
Instructor
10 Year Member
Liked
Loved
 
Joined: Apr 2015
Posts: 196
Likes: 26
Default Transmission upgrade?

1971 LS-6, over 600hp. The Muncie is not cutting it. I'm running 355's in the rear and at 70 its turning about 3000 rpm. Is a five speed my only option? what would be the cost on a TKO five speed out the door.
Thanks, John.
Reply
Old Sep 6, 2015 | 03:15 PM
  #2  
cagotzmann's Avatar
cagotzmann
Melting Slicks
10 Year Member
Liked
Top Answer: 1
Top Answer: 3
 
Joined: Jun 2011
Posts: 3,114
Likes: 597
Default

Originally Posted by 084273lz
1971 LS-6, over 600hp. The Muncie is not cutting it. I'm running 355's in the rear and at 70 its turning about 3000 rpm. Is a five speed my only option? what would be the cost on a TKO five speed out the door.
Thanks, John.
TKO 600 max torque is only 600 ftlbs. T56 Magnum is 700.

Hold out for a 6 speed conversion. This is a email I got from Silversport

Note the 6 speed conversion kit coming soon ?


http://campaign.r20.constantcontact....6-d4ae5292b9a6

I did a 3 speed auto to a Tremec T56 Magnum this last spring.

I used parts from a number of vendors with a few mods. The 6 speed (T56 Magnum) rated at 700 ftlbs will be a good fit for your engine.

https://www.corvetteforum.com/forums...-corvette.html
Reply
Old Sep 6, 2015 | 04:11 PM
  #3  
GTOguy's Avatar
GTOguy
Race Director
Liked
Loved
Community Favorite
Top Answer: 1
 
Joined: Apr 2015
Posts: 17,571
Likes: 3,459
From: Fresno California
Default

A much cheaper and easier option is to swap the 3.55's for some 3.08's. With your power and torque, you don't need a steep rear gear. 3.08's will put you right where you want to be in pretty much any driving situation.
Reply
Old Sep 6, 2015 | 04:18 PM
  #4  
mrvette's Avatar
mrvette
Team Owner
Active Streak: 120 Days
Liked
Loved
Community Favorite
 
Joined: Jul 1999
Posts: 65,492
Likes: 230
From: Orange Park Florida
Default

Originally Posted by GTOguy
A much cheaper and easier option is to swap the 3.55's for some 3.08's. With your power and torque, you don't need a steep rear gear. 3.08's will put you right where you want to be in pretty much any driving situation.
AND I have a 308 R&P I willing to sell the OP.....send me a PM if interested......

Reply
Old Sep 7, 2015 | 10:43 AM
  #5  
carbster09's Avatar
carbster09
Burning Brakes
15 Year Member
 
Joined: Oct 2002
Posts: 914
Likes: 14
From: Aberdeen, Scotland
Default

What about a rebuild of your transmission with M-22Z gearing? Then you can run a 3.08 or even a 2.73. With that power and torque it should be no problem. cheaper too!
Check out Jody's Transmissions. I was thinking of doing the same in my build BBC
Reply
Old Sep 7, 2015 | 03:09 PM
  #6  
Ibanez540r's Avatar
Ibanez540r
Drifting
Supporting Member
10 Year Member
Liked
 
Joined: Oct 2012
Posts: 1,524
Likes: 61
From: Medina Ohio
Default

Originally Posted by cagotzmann
TKO 600 max torque is only 600 ftlbs. T56 Magnum is 700.

Hold out for a 6 speed conversion. This is a email I got from Silversport

Note the 6 speed conversion kit coming soon ?


http://campaign.r20.constantcontact....6-d4ae5292b9a6

I did a 3 speed auto to a Tremec T56 Magnum this last spring.

I used parts from a number of vendors with a few mods. The 6 speed (T56 Magnum) rated at 700 ftlbs will be a good fit for your engine.

https://www.corvetteforum.com/forums...-corvette.html
ONLY 600 TQ? Like that is not an impressive number compared to most trannies?

The 600 TQ comes from SUSTAINED testing, and as most manufacturer specs I assume is a SAFE number. Not many motors are going to hold that kind of TQ through the curve, rather peak for short times where the TKO will handle fine.

Either the 5 or 6 speed is a good choice. Make sure to calculate ratios with your rear gear to decide what suits your needs. The 5 speed has the same 1-4 with either a .63 or .82 OD. The 6 speed, I believe, comes in a wide and close ratio combination.

I pieced my "kit" together, but I think if you buy the ready to go TKO package your looking at around $4k

Last edited by Ibanez540r; Sep 7, 2015 at 03:12 PM.
Reply

Get notified of new replies

To Transmission upgrade?





All times are GMT -4. The time now is 08:16 PM.

story-0
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter

Slideshow: From C1 to C8 we compare every Corvette generation by the numbers.

By Joe Kucinski | 2026-05-12 16:54:12


VIEW MORE
story-1
8 Coolest Corvette Pace Cars (and Replicas) of All Time

Slideshow: Some Corvette pace cars became collectible legends, while others perfectly captured the look and attitude of their era.

By Verdad Gallardo | 2026-05-11 09:50:51


VIEW MORE
story-2
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)

Slideshow: Ranking the top 10 Corvette engines by torque output.

By Joe Kucinski | 2026-05-05 11:58:09


VIEW MORE
story-3
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!

Slideshow: A Corvette pace car nearly matching IndyCar speeds sounds exaggerated, until you look at the numbers.

By Verdad Gallardo | 2026-05-04 20:03:36


VIEW MORE
story-4
Top 10 Corvettes Coming to Mecum Indy 2026!

Among a rather large group of them.

By Brett Foote | 2026-05-04 13:56:44


VIEW MORE
story-5
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!

Slideshow: the top 10 things Corvette owners want in the C9 Corvette

By Michael S. Palmer | 2026-04-30 12:41:15


VIEW MORE
story-6
10 Revolutionary 'Corvette Firsts' Most People Don't Know

Slideshow: 10 Important Corvette 'firsts' that every fan should know.

By Joe Kucinski | 2026-04-29 17:02:16


VIEW MORE
story-7
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2

Slideshow: Should you buy a 2020-2026 Corvette or wait for 2027?

By Michael S. Palmer | 2026-04-22 10:08:58


VIEW MORE
story-8
2027 Corvette vs The World: Every C8 vs Its Closest Competitor

Slideshow: 2027 Corvette lineup vs the world.

By Joe Kucinski | 2026-04-24 16:12:42


VIEW MORE
story-9
10 Most Common Corvette Problems of the Last 20 Years!

Slideshow: 10 major Corvette problems from the last 20 years.

By Joe Kucinski | 2026-04-14 16:37:05


VIEW MORE