1968-1982 Corvette Automatic Overdrive Stage 3 (650 LB-FT)

Kit Components

A truly complete conversion, combining the Keisler PerfectFit^TM transmission system with all of the correct matched accessory parts that have been carefully selected and tested by Keisler for guaranteed quality and performance.

Drivetrain component selection and installation instruction and support is critical to get the job done right. Rest assured, buying from Keisler - the leader in overdrive transmission systems - is the first step in the best driving improvement you will make to your Corvette.

1. TRANSMISSION – Custom-engineered electronically controlled Hydra-Matic 4-Speed automatic overdrive, built to withstand today’s high-performance engines up to 650 LB-FT. of torque. Provides modern driving quality without sacrificing the stock look, with a 30% RPM drop in 4th gear (check out our Speed Analyzer). Gear ratios:

3.06:1 First
1.63:1 Second
1.00:1 Third
0.70:1 Fourth

Bonus: You can hold 1st gear by pulling the lever into 1, and get awesome launch control!

2. LOCK UP TORQUE CONVERTER – Electronically controlled to give you lower RPM’s, longer transmission life and quicker reaction to your right foot!

3. CROSSMEMBER – Heavy-duty formed steel, MIG welded box construction with powder coated finish.

4. ISOLATOR – Heavy-duty rubber isolator, polyurethane upgrade available.

5. TRANSMISSION CONTROLLER – Compact plug and play unit pre- programmed to match your driving style. Intelligent computer monitors your throttle and vehicle speed to provide transmission performance that meets your demands – from easy cruise with softer shifts – to tire blazing, spine tingling firm shifts – all in one transmission solution. The best of both worlds – comfort and performance!

6. DRIVESHAFT AND SLIP YOKE - Lightweight high strength steel, automatic welded and computer dynamic balanced with premium solid sealed U-joints and heavy-duty Spicer slip yoke, painted satin black, certified and serialized. Built in-house on Hines driveshaft manufacturing cell for the ultimate in quality and craftsmanship!

7. THROTTLE POSITION SENSOR (TPS) – Bolt-on unit provides throttle feedback to computer with just 3 wires. Eliminates the woes of yesteryear’s technology, such as mechanical kick-down linkages or Throttle Valve (TV) cables, which can be difficult to adjust by trial-and-error and will cause transmission damage if not adjusted properly.

8. SPEEDOMETER OUTPUT – Mechanical speedometer cable and correct driven gear, calibrated for your vehicle's tire size and differential ratio.

9. PLUG & PLAY HARNESS – Simple to install with all weather tight, modular connections.

10. SHIFTER CONVERSION KIT – Includes all necessary parts to convert your original 3-speed automatic shifter to a 4-speed shifter. Retains the original shifter handle, console, and top plate for a factory-original look.

11. DIPSTICK AND TUBE – Original Equipment style; Dress-up options available.

12. FLEXIBLE BRAIDED STAINLESS STEEL COOLER LINE SET – Replaces the factory rigid lines.

13. AUXILIARY TRANSMISSION OIL COOLER - Stage 2 and Stage 3 transmissions come with a high-performance auxiliary transmission oil cooler to help meet the demands of higher horsepower engines.

14. INSTALLATION HARDWARE – High strength Grade 5 and 8 fasteners, properly sorted, bagged and labeled for easy reference. Everything you will need – no trips to the local hardware store required!

15. INSTALLATION MANUAL – Easy to understand, highly illustrated instructions for a smooth installation.

16. 12 MONTH/12,000 MILE WARRANTY - Covers R&R labor and shipping - Best warranty in the business!

100% Customer Satisfaction Guaranteed

The best Customer and Tech Support in the industry

Lifetime Tech Support from our premier experienced staff

1968-1982 Corvette Automatic Overdrive Stage 3 (650 LB-FT)

Overview-Ordering

Click to enlarge

The Keisler 4-speed Automatic Overdrive System - the best upgrade available for your 1968-1982 Corvette. This complete transmission solution provides you the driving quality of a late model car, with a no-cut installation. It features the latest in plug-and-play electronic controls and is a PerfectFit with any Chevrolet Small Block, Big Block, or LS series engine. This is everything you need for a turn-key installation, and even retains the use of your original floor shift gear selector and console.

Enjoy the benefits of an automatic overdrive transmission now:

Faster acceleration – gets your Corvette moving quicker with a 3.06:1 first gear and engine-matched stall converter that makes your car more responsive and fun to drive.
Low RPM cruising – drops your engine RPM by over 30%, allowing you to keep your performance rear axle ratio and still drive on the highway (check out our Speed Analyzer).
Better fuel economy – up to 40% due to the overdrive fourth gear and the lockup torque converter.
Reduced engine wear – lower RPM equals less maintenance cost.
Optimum shift quality – late model Hydra-Matic technology.

Unsurpassed quality of design, components and build are included with every Keisler PerfectFit™ System. Enjoy low RPM cruising, while getting the benefits of reduced engine wear and tear. Join thousands of customers that say "The Keisler PerfectFit™ Transmission System is the Best Upgrade for your Corvette!"

Recommended Accessories (Have questions? Please call 865-609-8187 for assistance):

Paddle Shifter for Keisler A41 Automatic Overdrive System
Paddle Shifter for Keisler A41 Automatic Overdrive System allows you to shift gears manually F1-style without taking your hands off the wheel! Works great with the available Engine Braking Valve Body option on our A41 Automatic Overdrive.

Item Details

Price:
$699.95

ORDER BY PHONE:

Call 1-865-609-8187

Polyurethane Transmission Mount GM TKO, A41 All
High-Performance Polyurethane transmission mount for GM TKO and Automatic Overdrive, and Mopar Automatic Overdrive.

Item Details

Price:
$49.95

ORDER BY PHONE:

Call 1-865-609-8187

Speed Analyzer

Typical 3-speed automatic vs.
Keisler 4-speed automatic

New transmission:

Keisler 4-speed automatic (.70 OD)

1. Pick your tire size: / R-

2. Pick your cruising RPMs:

Results: The Best of Both Worlds!

Low Gear Acceleration AND Low RPM Cruising!

1st Gear Comparison		Final Gear Comparison
Stock Differential Ratio	Keisler Automatic Accelerates like:	Stock Final Gear	Keisler Automatic Overdrive
	rear	mph	mph
	rear	mph	mph
	rear	mph	mph
	rear	mph	mph
	rear	mph	mph
	rear	mph	mph
	rear	mph	mph
	rear	mph	mph
Rolling diameter for selected tire: inches
Keisler Gear Set:			Torque:
Chrysler 727 Gear Set: 1st=2.45:1; 2nd=1.45:1, 3rd=1:1, 4th=n/a Keisler 4-speed Auto. Gear Set: 1st=3.06:1, 2nd=1.63:1, 3rd=1:1, 4th=.70:1

Testimonials

Recent Testimonials...

Mike Campbell - '59 Corvette

Here's some pictures of my 59 Vette with a 520hp/427cu.in. fuel injected small block built by Pfaff Racing Engines hooked up to one of your Tremec 5 speeds, chassis built by Progressive Automotive, 2" dropped spindles, disc brakes, hyd. clutch, MSD ignition, Mattson alum radiator with electric fans, 9" Ford readend, positraction, American Racing wheels, took the door and window crank handles off, reworked the door posts to remove the window tracks and made custom pieces for the top of the doors to cover where the door glass was, the car is now a true roadster with no windows but can still put the hardtop or softtop on the car, custom machined billet valvecovers and air breather made to my design, all custom leather interior by Ron Mangus in CA. The car is an absolute BULLET!!!
Mike

See Mike's other car HERE !

Dwight Simon - '71 Vette

My happy story. After researching the various 5 speed companies offering a C3 Corvette conversion kit from an automatic to a 5 speed I choose Keisler Engineering for three reasons. 1. After a couple indepth conversations with Gene and Jeff at Keisler Engineering, I became convinced they offered the best COMPLETE KIT product. 2. ALL the parts required to change out my 700R4 trans to a five speed came in one kit. 3. Gene accurately recommended a competent local installer called Big Hemi Customs in Ft Wayne, In. At Big Hemi I spoke with Jason and became convinced they could complete the swap easily. Previously, the 454” small block from World Products was dyno’ed at the rear wheels with at 376 HP and 412 lbs of torque with the automatic. Gene suggested the TKO 600 with a 0.64 5th gear as the vette’s rear end is 4.11. He also helpfully suggested a few additional parts to really complete the install such as new tunnel insulation and new manual shift plate. I had The 5 speed kit shipped to Big Hemi whose crew did an outstanding job of making the swap. Attention to detail was super. By that I mean they repainted the shifter console and also fabricated new console support brackets making the install very professional looking. Additionally, when I dropped off the Vette at Big Hemi - Jason suggested swapping out the Holley carb for an EFI unit because of the cam overlap and idle problems I’ve had. Long story short – I purchased a Powerjection III EFI from Summit and had it sent to Big Hemi. They installed it easily and it runs real well. The trans allows me to cruise at 70 mph at 2100 rpm while the EFI makes the motor have civil street manors. I especially like the smooth shifting trans, zero vibration and stock looking shifter. I would strongly suggest the Keisler trans swap to anyone wanting to upgrade their pride and joy. I’ve include an assortment of pictures that you may use as you may see fit.
Thanks,
Dwight Simon

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