In order to understand what conversion mounts you need for your swap, you need to first understand SBC motor mount differences in your vehicle. 1970-1972 F-Bodies still used the Early Style SBC motor mounts. 1973 is the first year they transitioned into the Clam Shell Mount Style. 1970-72 Camaro’s that came from the factory with a SBC typically used Short and Wides while Camaro’s with a BBC used Tall and Narrow. You may come across an instance where a previous owner has installed Frame Perches from a different vehicle so it is important to understand both types.
A- Frame Perch, B- Early Style SBC/BBC Motor Mount, C- LS Conversion Mount
This example photo is from an Impala, your Frame Perch will look different.
This usually sparks the question, "Which one is better?". If sticking to rubber, the Tall and Narrow has more rubber to further dampen any vibrations. If going poly, its the same either way. If you spent the time and money to swap from Short and Wide to Tall and Narrow, you wouldn't really notice that big of a difference. If you look at the following example comparison photo, you can see the end result in height is about the same. Meaning it's not worth the money to convert what you currently have to the other style for something such as oil pan clearance. Use what you got and stop stressing over which one is best. The bolt pattern to the block side of the Early Style is the exact same and doesn't make a difference when choosing your conversion mount.
Every SBC/BBC GEN 1 has the same exact bolt pattern on the block for motor mounts. They never changed the engine side. The following photo's through-bolt hole with the dotted line is the easiest measurement to use to compare with your existing setup. Measure the width of your Frame Perch and then match it with one of the following SBC Early Style motor mounts.
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)
Tall And Narrow
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)
Early Style SBC motor mounts on their matched Frame Perch. Notice how they are about identical in height in the end.
OEM rubber motor mounts last much longer than aftermarkert rubber. Poly mounts essentially last a lifetime and don't need to be replaced.
Reproduction Chevrolet V8 Frame Perches:
’70-72 Camaro Big Block
*These are only direct bolt in for 1970-72 F-Bodies. You can also use these on 73-81's but you will have to mock them up and drill new holes in the cross member..
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 reffered to as the Clam Shell. 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 Clam Shell Style started to phase out the Early Style Short and Wide/Tall and Narrow's in 1972.
OER makes reproduction Clam Shells but you have to understand that they are not a one size fits all. 2WD and 4WD 1973-1987 C10 will not interchange for instance. If you are removing the Clam Shells for any reason, such as replacing the Clam Shell Mount, don't forget to label them as passenger and driver side so the install is much easier.
LT GEN III/IV Conversion Mount Options 70-72:
Comes in plain steel which will rust over time so make sure you paint it before the final install or we can powdercoat it black for an additional fee.
*Requires modification to the Clam Shell if not using the very front holes for OEM location
*Requires modification to the Clam Shell if not using the very front holes for OEM location
*Not compatible with low mount AC
*No modification required to the clamshell
LT GEN III/IV Conversion Mount Options 73-81:
*Does NOT require factory outerClamshell
LT GEN V Conversion Mount Options 70-72:
*Not compatible with low mount AC and passenger side motor mount requires a notch on the lower side
LT GEN V Conversion Mount Options 73-81:
DD-6500C
*Does NOT require factory outer Clamshell
LS Oil Pan Options:
F body pans with a modfication to the front of the sump will fit. These Holley pans are basically modified F body pans.
Holley 302-2
Holley 302-3
LT Oil pan Options:
Holley 302-20
Power Steering
All the way up to 1979, the factory gearbox takes an inverted flare fitting. It is quite common to find a newer gearbox isntalled with a metric o-ring fitting instead. Use the following information to figure out what fittings you need for your power steering lines.
|
|
Pressure |
Return |
|
LS Power Steering Pump |
M16x1.5 O-Ring |
Hose Clamp |
|
Before 1980 Gearbox (SAE) |
5/8"-18 |
11/16"-18 |
|
After 1980 Gearbox (Metric O-Ring) |
M16x1.5 O-Ring |
M18x1.5 O-Ring |
If your O-ring is old and hard, use the following part number for replacements: GM 26001594
DO NOT use any O-ring you find at the parts store. The Metric O-Ring fitting requires an O-Ring made of Viton so the power steering fluid doesn't destroy them.
O-Ring Technical Info: 903 (7.65mm ID x 1.63mm C/S or .301 ID x .064 C/S) Viton
If your vehicle has the Metric O-Ring fittings, then your power steering lines will bolt straight up to any power steering pump offered in an LS application. Make sure there isn't an O-ring already in the power steering pump from the old line!
If your vehicle has the SAE fittings AND the 3/8" lines line up to the back of your LS power steering pump, all you need is THIS ADAPTER to be threaded into the high pressure port on the pump. The power steering pump side is M16x1.5 with a Viton O-Ring while the power steering line will fit a 5/8"-18 Inverted Flare.
3/8" Line threaded into the adapter fitting on the back of an LS truck power steering P pump with THIS ADAPTER
Check out Lee Power Steering for all your GM gearbox needs. They can rebuild and do precise valve tuning to give you that exact steering you are looking for!
Second Generation Pontiac F Body with a Pontiac V8 in it have a different steering setup. They have a lower pitman arm which would help clear a low mount alternator. You can use a Pontiac pitman arm on a Camaro but you have to change the crosslink and the inner tie rods to Pontiac as well. Make sure you have parts from a V8 car!
Pontiac V8 lower dropped pitman arm shown in photo with clearance to a low mount alternator. The Camaro pitman arm is straight in comparison to this drop and may cause fitment issues.
