Corvette Racing
Duntov Motor Co


Duntov Motor Company, LLC

13906-C Denton Drive
Farmers Branch, TX 75234

Toll Free Order Line
(888) 581-3838

Phone (972) 243-3838

Fax (972) 243-3828

Sportscar Vintage Racing

Lake Forest Sportscars
Corvette Grand Sport
Duntov Motor Company

SCCA champion Alan Sevadjian in the #38 GT1 Corvette
In road racing
, you get a lot of practice building rear ends. In thirty years of racing with these differentials, we had only one failure. We sheared the ring gear bolts smooth off at the Detroit Grand Prix. We fed almost 700 HP through stock stub axles and spindles, and they never broke. This is one great piece of equipment.

63-79 Differentials
1963-79 Corvette DifferentialOur remanufactured differentials are sold with no core charge. We will ship freight free within the Continental US in a reusable heavy-duty box. You can use the box to send in your old differential, or you can keep it.

If the exterior of your differential appears OK, and there are no apparent defects, its total core value would fall between $100 and $400. See the core value menu for details. The freight back on your old unit is your responsibility.

All our differentials come with new ring and pinions, as well as new GM stub axles, and a GM cover, Timken bearings, seals, and an Eaton clutch pack. They are shipped complete with fill plug, and are guaranteed to perform perfectly under normal conditions and use for three years. Note: UPS won't let us fill them with oil, so they are shipped with NO OIL.

* If you want to save a few bucks, we may have the used gearset you want in stock. If we have it, we can supply any three series differential equipped just like our standard units, but with a used ring and pinion, stock rear cover and stub axles for $1499. We will not reuse a gearset with more than 1/2 of the pattern showing wear. Check stock for used gearsets.

Remember, No Core Charge, and No Freight


3.08 63-79 Differential - $2196
3.36 63-79 Differential - $2196
3.55 63-79 Differential - $2196
3.70 63-79 Differential - $2196
3.90 63-79 Differential - $2548
4.11 63-79 Differential - $2298
4.33 63-79 Differential - $2298
4.56 63-79 Differential - $2298
Differential Options
D011 new style Eaton carrier with carbon fiber clutch packAdd for New Eaton Style Posi Carrier with Composite Clutch Pack
add for $540

D011 new style Eaton carrier with carbon fiber clutch packThese ‘heavy duty’ rear covers are a solution looking for a problem. Breaking a cast iron rear cover is very rare. These weigh 21.5 lbs, 5 pounds heavier then stock. We run a stock cover in our racecar, but if you want a heavy rear cover on your new differential from Duntov, click on this.
add for $119

D013 carbon fiber clutch pack and plate setAdd for Carbon Fiber  Clutch Pack and Plate Set 
(for the stock carrier)

add for $92

Racing and High Performance Options

Depiction of REM treatment on the Ring and Pinion Gears
Before REM Treatment After REM Treatment  
The REM treatment shown on the ring and pinion of part #'s D014 & D015 is remarkable. The physicochemical process used to achieve this finish utilizes high density, non abrasive ceramic media and vibratory finishing equipment. The process removes microscopic surface asperities that are inherent in any machining process. The resultant part looks like it is chrome plated, but nothing is added to the part’s surface.

NASCAR engine internals are almost all REM coated, as is every moving part of their transmissions and differentials. We REM coat virtually everything in our racecar’s driveline, and the results have been significant. Gear sets last longer, differential oil temperatures are reduced, and horsepower loss in the driveline is way down.

D014 REM coated ring and pinion optionAdd for REM Treated Ring and Pinion
add for $198
D015 REM racecar application option for the differentialAdd for
Racing Prep

add for $1656
•  REM ring & pinion
•  New Eaton Carrier
•  800 LB Preload Kit
•  Steel Clutch Plates
•  ARP Ring Gear Bolts
•  Super-Duty Axles
•  Racing Set-up Specs
D016 option for Diff cooling with drain fitting in the caseAdd for Diff Cooling with drain fitting in the case
(not shown)
add for $167
63-79 Corvette Differential Core Values
There is no core charge! If you want to send back your old differential in the fine box we send your new one in, this is the guide we will use to determine its value. When we get your core, we will disassemble, inspect and pay you for everything in there that is good enough to use in one of our differentials.
Case with No Damage
Rear Cover
Pinion Flange   $35
Sub Axles (pair)*
Posi Carrier
Good Reusable Ring and Pinion Sets
* we don't reuse stub axles, but they have core value, so we will pay you and pass them on.
1963-79 Corvette loaded posi carrier new by Eaton63-79 New Loaded Posi Carrier

This is an all new Eaton Style Posi carrier, and it is a vast improvement over the original equipment Eaton design. This carrier is loaded, meaning it is set up by the factory with new spider gears, heavy duty plates and springs and the new composite clutch pack. If you are building a differential for heavy duty applications, this is a good investment.
Free Freight
3 Series Carrier

1963-79 Corvette new ring and pinion gear sets63-79 New Ring & Pinion Gearsets

We use Richmond, US Gear and Yukon gearsets, as not all ratios are available from all manufacturers. Specify ratio. 4.11 gearsets are available for either the three series carrier or four series carrier.
Free Freight

3.08 Ring and Pinion Gear Set
3.36 Ring and Pinion Gear Set
3.55 Ring and Pinion Gear Set
3.70 Ring and Pinion Gear Set
3.90 Ring and Pinion Gear Set
4.11 - Thick Ring and Pinion Set
4.33 - Thick Ring and Pinion Set
REM coated ring and pinion optionAdd for REM Treated
Ring and Pinion

add for $198

D034 1963-79 Corvette differential overhaul kit63-79 Complete Differential Overhaul Kit
Kit includes bearings, seals, shims, LocTite, pattern paint, ring gear bolts and a gasket. There are a few extra parts in the kit (not shown), but rest assured, they are included at no extra charge!
Free Freight

63-79 Differential Overhaul Kit

D035 1965-79 Corvette Eaton differential shim set65-79 Eaton Differential Shim Set

This should be all the shims you will ever need to set up your Corvette differential. There are 4 carrier shims, 10 side shims and 10 pinion shims.

65-79 Eaton Differential Shim Set
1963-79 Heavy duty Corvette differential coverHD 63-79 Differential Cover

This part is not for preventative maintenance. If your stock cover is OK, don't replace it. This thing is bullet proof, but breaking the stock rear cover is almost unheard of. The Grand Sport got along fine with an aluminum rear cover. This one weighs 20 lbs vs. the stock cover at 16. It comes with a gasket and a new breather, but if you don't want to use your old drain plug, you need to order one of those too.

Free Freight
63-77 HD Rear Cover
78-79 Differential Cover
Fill Plug
1963-79 Stock Corvette differential coverStock 63-79 Differential Cover

These are selected stock covers, sandblasted and painted with Cast Blast, shipped with a gasket and breather. Some late 77's came with 2-1/2 inch rear springs, and for those cars, select part number D048.

Free Freight
63-77 Stock Cover
78-79 Stock Cover
63-79 HD Cover with AN Fittings

The best way to plumb your differential for cooling lines is to tap the bottom of the case for the scavenge line, but we ran this setup for years and it worked just fine. This is an OPTION, and unless you get a rear cover, there won't be anything to mount these fittings in! This option includes 3 mounted dash 6 aluminum fittings.

Free Freight
63-79 HD Cover with AN Fittings
Heavy duty Corvette carbon fiber posi clutch kitHD Carbon Fiber Posi Clutch Kit

This part was developed by Eaton to increase hook-up and reduce chatter. The more spring you use the more the unit will transfer power to both wheels. The springs in a standard Posi unit are weak and the end plates are thin. When whale oil was outlawed in the seventies, the spring tension had to be further reduced to eliminate chatter. These end plates are thick and the springs are twice as heavy as the stock units, but with carbon fiber clutch discs, there is no chatter. We package this set with two 40 thousandths shims, so it should be a direct replacement for your old steel clutch pack.
Free Freight
HD Carbon Fiber Posi Clutch Kit
Corvette steel posi clutch kitsSteel Posi Clutch Kits
These kits comes with new springs, plates, steel clutch discs and stays. The 200 lb. kit is for a stock installation. The 800 lb kit has special heavy duty plates and springs and is intended for racing aplications only.

Check here for an exploded view of the Eaton Posi unit.

Free Freight
OEM 200 lb. Posi Clutch Kit
Racing 800 lb. Posi Clutch Kit
63-79 Reman Carrier63-79 Reman Carrier
63-79 Reman Carrier
1965-79 Corvette pinion crush sleeve65-79 Pinion Crush Sleeve
65-79 Pinion Crush Sleeve
1965-79 Corvette differential pinion flanges65-79 Differential Pinion Flanges

These are reconditioned flanges, guaranteed to be perfect. The 65-70 unit is 3 7/8 inch across, while the 68-79 is the larger size, at just over 4 1/4 inches across.
Big 68-79
Small 65-70
1963-79 Corvette Stub Axels63-79 Stub Axles

These are NEW GM differential carrier axle yokes. The HD threaded units are
GM part # 3872922, while the U bolt style is GM part # 14016436.

Free Freight
One Threaded Stub Axle
One U Bolt Style Stub Axle
Heavy duty Corvette stub axle capsHD Stub Axle Caps

These come with Grade 8 bolts and washers. They fit the original equipment D081 HD stub axles. This is enough for one stub axle. You will need to order 2 for a car set!
1 Stub Axle Set: 2 Caps, 4 Bolts and Washers
1963-79 Corvette super duty stub axles63-79 Super Duty Stub Axles

These are for applications north of 600HP. They are sold individually, and are priced EACH. They come as shown with Heavy Duty caps and Grade 8 bolts.

Free Freight
One Super Duty Stub Axle
1963-79 Corvette half shaft assembly63-79 Half Shaft Assembly

This assembly is all GM, with Spicer maintenance-free U joints.

Free Freight
One 3 Inch Diameter Half Shaft Assembly
One 2.5 Inch Diameter Half Shaft Assembly
1963-79 Corvette half shaft63-79 Half Shaft

These are reconditioned GM parts. You have your choice of the later model 3 inch diameter tubes, or the early model 2 1/2 inch shafts.
One 3 Inch Diameter Half Shaft
One 2.5 Inch Diameter Half Shaft
1963-79 Corvette Half shaft flange63-79 Half Shaft Flange

This is a perfectly straight, reconditioned GM Spicer half shaft flange.
63-79 Half Shaft Flange
1963-79 Corvette Spicer u-joints63-79 U Joints

These are the proper style Spicer U joints with no grease fitting,
sold in pairs.

63-79 Halfshaft


68-70 Auto Driveshaft or 71-79 Driveshaft


63-67 Driveshaft or 68-70 4-Speed Driveshaft

1963-79 Corvette offset driveshaft u-joint63-79 Offset Driveshaft U Joint

If you are trying to match up a small driveshaft with a large differential pinion yoke, or vice versa, this little offset U Joint will save you a big headache.
63-79 Offset Driveshaft U Joint
1963-79 Corvette front differencial mount set63-79 Front Differential Mount Set

Original molded OEM upper and lower Rubber Bushings fused to steel, with bolt, nut and washers, or choose the harder Poly Bushing.

OEM Diff Bushing


Poly Diff Bushing

1963-79 Corvette differential crossmember bushings63-79 Diff Crossmember Bushings

These are sold by the Pair, as shown.
Free Freight

(2) Diff Xmbr Bushings

Corvette loaded differential crossmemberLoaded Differential Crossmember

If your differential crossmember is rusted out, you may want to go with one of these. They are rust free reconditioned units with new bushings installed. Free Freight

63-77 Loaded Xmbr


78-79 Loaded Xmbr

Royal Purple gear lube
3 Quarts of Royal Purple
Gear Lube