GM vehicles made prior to 1958 did not use motor mounts on the side of the engine. For these applications, check out our Universal Mount Solutions. For 55-57 Tri-Fives. We make conversion frame side brackets to convert them to use engine mounts on the sides of the block.
In order to understand what conversion mount you need for your project, you need to have a better understanding of Chevrolet V8 motor mounts for your vehicle.
GM V8 Early Style Motor Mounts 1955-1972
1955-1972 Small and Big Block Chevrolet engines use the same style 3 bolt engine mounts, other than 60-72 C10's. Early Style SBC/BBC Gen 1 engine mounts available today are classified as Short and Wide or Tall and Narrow. In order to install your Early Style SBC/BBC motor mount, you need a Chevy V8 Frame Perch. You need to understand the differences in the Early Style mounts and their matching Frame Perch so you can make sure you are buying the correct SBC/BBC motor mounts. Our Info By Model section will state the OEM SBC/BBC motor mount part numbers but you may come across an instance where a previous owner has installed Frame Perches from a different vehicle.
A- Frame Perch, B- Early Style SBC/BBC Motor Mount, C- LS Conversion Mount
Frame Perches may also be referred to as towers, mounts, and stands. It's the upraised piece that allows you to mount the SBC/BBC rubber/poly motor mount.
Early Style Motor Mounts come in three different versions. Short and Wide, Tall and Narrow, and then there's the odd ball 1960-1972 C10 SBC motor mount with a vertical through-bolt.
As you can see in the example photo above of the Early Style on their matched Frame Perch, there is not much difference in height after fully assembled. Don't worry about changing from one to another for something such as oil pan clearance. Not all applications will have both styles. Just measure what you got and match the Early Style to your Frame Perch. You can't just take an A-Body Frame Perch and bolt it down your B-Body. They do not directly interchange. In some cases you may come across a vehicle that has had this done by a previous owner to convert their vehicle to a Chevy V8 and they welded or drilled holes in the engine crossmember to get it to work.
If you have a non-V8 Chevy vehicle or GM non-Chevy vehicle, you have to acquire the Chevy version of V8 motor mounts for that year range GM body style. That means the Frame Perches and the matching SBC/BBC motor mount. Or if we are talking about 1973-99 GM vehicles, then you need the Clamshell Mount and the matching Clamshell itself. You can learn more about those further down on this same page. For example, if you have a 1968 Pontiac GTO (GM A-Body), then you need to remove the Pontiac motor mounts and Frame Perches off the engine cross member and purchase 1968-1972 Chevelle frame perches as that is the A-body Chevy equivalent. Even though it is a Pontiac, it will still have the bolt holes on the engine cross member for Chevrolet V8 frame mounts.
Check out our Info By Model section for direct links to well known reproduction Chevy V8 Frame Perches. If you can't find V8 Chevy frame mounts for your application, then check out this Clamshell Mount Method. Your vehicle may have already been converted to the later Clamshell Style Mounts, scroll further down and read about them as well.
Short And Wide
OEM Part Numbers(Rubber): 3990914, 3960768, 6258154
Aftermarket Part Numbers(Rubber): 2142, 2285, 2267
Energy Suspension (Poly): 3.1114 Zinc, 3.1115 Chrome (G-Black, R-Red)
OEM Part Numbers(Rubber): 3962740, 3990918, 3962748
Aftermarket Part Number(Rubber): 2283
Energy Suspension (Poly): 3.1117 Zinc, 3.1118 Chrome (G-Black, R-Red)
A lot of aftermarket front clips from companies such as Total Cost Involved (TCI) are designed to run the Early Style, Short and Wide motor mounts on a welded tubular piece for the through-bolt.
TCI Mustang II IFS setup with the tubular through-bolt piece for a Short and Wide
63-72 V8 C10 Using 67-72 V8 Frame Perches
1960-72 C10's used a SBC motor mount with the through bolt going vertical, instead of the normal horizontal through-bolt. They will utilize the same style conversion mounts. Late model 1972 BBC C10's used the later Clamshell Style.
SBC Aftermarket(Rubber): WESTAR EM2282, DEA / MARMON RIDE CONTROL A2239, ANCHOR 2282, PIONEER 602239
SBC Energy Suspension(Poly): 3.1156 (G-Black, R-Red)
Once you have the Chevy V8 Frame Perch and the matching Early Style motor mount, you need to choose your conversion mount.
LS GEN III/IV Conversion Mount Options:
Comes in plain steel which will rust over time so make sure you paint it before the final install or we can powder coat it black for an additional fee.
*The rectangular holes in the center of the conversion mount allows you to bolt up a Clamshell in the factory SBC location without modifications. Factory SBC location is the farthest forward holes on this mount. If using other locations, you may have to sand down the Clamshell to have a flat surface in order to bolt it down properly.
*The rectangular holes in the center of the conversion mount allows you to bolt up a Clamshell in the factory SBC location without modifications. Factory SBC location is the fartherst forward holes on this mount. If using other locations, you may have to sand down the Clamshell to have a flat surface in order to bolt it down properly.
*Not compatible with low mount AC
*No modification required to the Clamshell
LT GEN V Conversion Mount Options:
*The rectangular holes in the center of the conversion mount allows you to bolt up a Clamshell in the factory SBC location without modifications. Factory SBC location is the fartherst forward holes on this mount. If using other locations, you may have to sand down the Clamshell to have a flat surface in order to bolt it down properly.
*Not compatible with low mount AC
*No modification required to the Clamshell
Solid Motor Mounts
If you already have the above conversion mounts and want to run solid motor mounts instead of the rubber or poly options, check out Moroso's Solid Steel SBC Motor Mount Chart. Otherwise check out our Muscle Mounts to bypass the hassle of getting the correct sized SBC steel motor mount.
GM V8 Clamshell Style 1972-99
The motor mount and motor mount bracket in the following photo goes by a lot of names. A and B make up the Clamshell Style engine mount. GM refers to A as engine mount and B as a bracket. Nowadays, A is most commonly referred to as engine mount while B is most commonly referred to as the Clamshell. Engine mount is a loose term however and in order to not confuse the style of motor mount you have with the Early Style, you can refer to them as the Clamshell Mount. A can also be referred to as: rubber isolator, rubber mount, SBC/V8 engine/motor mount, "mounting, engine". B can also be referred to as: buckets, elephant ears, cups, motor/engine mount bracket, "bracket, engine mount", "bracket, engine mt". The Clamshell Style started to phase out the Early Style Short and Wide/Tall and Narrow's in 1972.
OER makes reproduction Clamshells but you have to understand that they are not a one size fits all. They are just as different to their application as Frame Perches are for 1972 and older GM vehicles. 2WD and 4WD 1973-1987 C10 will not interchange for instance. If you are removing the Clamshells for any reason, such as replacing the Clamshell Mount, don't forget to label them as passenger and driver side so the install is much easier.
The Clamshell Mounts and the Clamshells themselves will vary depending on application. SBC's typically used a 4-bolt Clamshell Mount while the BBC's and Diesels typically used a 3-bolt Clamshell Mount. If you have the Clamshell Mount and the Clamshell, you can use the conversion mounts already listed above. Some Clamshells need to be sanded down to a flat surface before bolting them to the conversion mount unless using the DD-Sliders/DD-LT-Gliders.
However most people prefer the EZ Mounts that are talked about further on down on this page with an application chart.
4-bolt Style Clamshell Mounts have mounting holes for bolts on all four corners. Often only three holes are used. Not to be confused with the 3 bolt style Clamshell Mounts where they only have 3 mounting bolt holes.
A- Mounting bolt holes that are flush to the engine cross member/V8 frame perch
B- Rivets/welds holding the clamshell together.
There are a couple of different poly inserts for Clamshell Mounts.
4 Bolt Style
Energy Suspension part number 3.1116 (G-Black, R-Red)
Replaces the inserts of the following G.M. type mounts: 14039437, 9762326, 467422, 1001132, 10001133, 9764714, 459021
Replaces the inserts of the following Aftermarket type mounts: 2292
3 Bolt Style
Energy Suspension part number 3.1121 (G-Black, R-Red)
Replaces the inserts of the following G.M. type mounts: 14071939, 22145334, 22188393, 334941, 357717, 3993721
Replaces the inserts of the following Aftermarket type mounts: 2395
1988-98 GM 2WD Trucks
Replaces the inserts of the following G.M. type mounts: 15529450, 15529451, 15529452, 15731260, 22188659
Replaces the inserts of the following Aftermarket type mounts: 2621
*2621's are more expensive as they are only used in one generation of GM Trucks. 2621 and 2395 are not directly interchangeable, but they are the same exact bolt pattern and take the same exact poly insert. You can run 2395's in 1988-98 Chevy trucks if you flip the rubber isolator around. You will have to drill out the rivets/welds to separate the metal housing just as if you were going to install poly inserts.
1988-00 4WD V8 and Diesel 3 Bolt Stepped Style
Energy Suspension part number: 3.1152 (G-Black, R-Red)
Replaces the inserts of the following G.M. type mounts: 15659675, 15732188
Replaces the inserts of the following Aftermarket type mounts: 2637
1998-2002 Camaro/Firebird Style
Energy Suspension part number 3.1151 (G-Black, R-Red)
Replaces the inserts of the following G.M. type mounts: GM GENUINE 22179268
*We currently only sell the black graphite ones poly inserts
Poly Insert Install Instructions
*If utilizing the stock Clamshell piece as well, make sure you orient the metal tabs the same as the OEM ones you removed. The tab higher up goes to the middle of the engine cross member to orient the Clamshells into a V shape so they run parallel to the sides of a SBC.
If you have a GM non Chevy vehicle or a Chevy vehicle that did not start out as a V8, you have to acquire the Chevy version of V8 motor mounts for that year range GM body style. That means the Clamshell Mount AND the CORRECT Clamshells. You can still buy the Clamshell Mount from local parts store, but you will have to source the Clamshell itself. The problem with that is that there is many different types and they are not all interchangeable and most of them are no longer available. Don't forget they are driver/passenger specific! We have solved this issue with the Dirty Dingo EZ Mounts. You may find people referring to them as the Dingo Sliders, which causes confusion as you have already seen that we have a part number DD-Slider. We can differentiate which style slider you are trying to get if you let us know you have the Early Style or the Clamshell Style without the Clamshell itself.
EZ Mount in a Square Body C10 utilizing a Poly Insert for the Clamshell Mount
Use the following links for an EZ Mount application chart
Other than GM
4.6L Ford V8 for Mustang LS Swaps
Ford OEM Genuine: 2R3Z-6038-AB (Right)/2R3Z-6038-AA(Left)
Aftermarket(Rubber): WESTAR EM3001(Right)/EM3002(Left), DEA / MARMON RIDE CONTROL A3001(Right)/A3002(Left), ANCHOR 3001(Right)/3002(Left),
4.6L Ford Poly Energy Suspension Poly Mounts 4.1127 (G-Black, R-Red) comes with passenger and driver side
*Customers have reported these work on 94-95 Mustangs.
Rubber Vs Polyurethane Motor Mounts
Why choose Energy Suspension and transmission mounts over rubber? The biggest reason is the safety interlock. Take a look at the following photos to see the molded-in safety interlock. If anything crazy happens and the poly rips or melts from a fire, the safety interlock will still hold your engine down. The OEM or aftermarket rubber mounts would split in half and your engine would be flopping around like a fish causing a lot of havoc in the engine bay.
This is one of the reasons you will see people converting their Early Style SBC motor mounts to the Clamshell Style. Even if the rubber deteriorates, the engine is still held in place by the metal housing holding what was left of the rubber isolator. Aftermarket Clamshell Mounts rubber isolator tend to sag over time or become unseated entirely from the middle. GM Clamshell Mounts last much longer than the aftermarket, but with the much higher price it is cheaper to use the Energy Suspension Poly inserts. Poly lasts longer and is more performance oriented. A stock GM Clamshell Mount metal housing is made of thicker material than these aftermarket Clamshell Mount metal housings and it is preferred to clean up an old dirty OEM Clamshell Mount metal housing than to buy a new aftermarket one with the poly insert.
"Original Equipment Manufacturers (OEM) choose to use rubber in their bushings for several reasons, including costs and comfort characteristics. Rubber offers less NVH (noise, vibration, and harshness) since it is soft and compliant, however, during spirited driving, the pliability allows for changes in alignment during acceleration, braking, and hard cornering.
Much like your rubber tires, rubber bushings wear out, especially when considering common factors such as heat and harsh fluids. Rubber bushings with direct UV exposure will dry out, crack, and rot, causing vital suspension components to function poorly. Some OE replacement parts use lesser quality grade rubber which will wear and fail quicker than the OE factory rubber.
Unlike rubber, our Hyper-Flex™ polyurethane is extremely resistant to harsh fluids. Our bushings will not dry out, rot, or crack from heat or UV exposure. Polyurethane offers superior precision during spirited driving, eliminating deflection caused by the soft pliability of rubber."
PowerFlex Comparison Chart
What's the difference between red and black Energy Suspension motor mounts? Black has graphite which adds a lubrication property. Red will squeak over time unless lubricated. Energy Suspension recommends their Formula 5 pre-lube.
How stiff are they? Energy Suspension are all at 70A-70T Durometer. Prothane mounts in comparison are at 80A.
