G8 Difference between LS3 and L76 intake manifolds
03-05-2015, 01:19 PM
#1
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G8 Difference between LS3 and L76 intake manifolds Some customers have asked us the difference between the L76 and the LS3 intake manifolds. We thought it would be helpful to forum members to post some pictures showing the differences.
First, side by side they look virtually the same. The throttle body opening is 90mm on both.
L76 on left LS3 on right
The runner port dimensions are identical (1.25"w x 2.475"h).
Illustration courtesy of CompCams
The part numbers are different.
L76 Part Number
LS3 Part Number
The easiest way to distinguish them is to look at the MAP Sensor mount on the left side of the throttle body opening as you face the front of the manifold. The L76 is mounted with a clip whereas the LS3 is mounted with a screw.
L76 MAP Sensor mount
LS3 MAP Sensor mount
Other than the MAP Sensor, the two manifolds are interchangable and they flow the same.
First, side by side they look virtually the same. The throttle body opening is 90mm on both.
L76 on left LS3 on right
The runner port dimensions are identical (1.25"w x 2.475"h).
Illustration courtesy of CompCams
The part numbers are different.
L76 Part Number
LS3 Part Number
The easiest way to distinguish them is to look at the MAP Sensor mount on the left side of the throttle body opening as you face the front of the manifold. The L76 is mounted with a clip whereas the LS3 is mounted with a screw.
L76 MAP Sensor mount
LS3 MAP Sensor mount
Other than the MAP Sensor, the two manifolds are interchangable and they flow the same.
03-06-2015, 02:40 PM
#2
Something is amiss here... I've owned 3 G8's and worked on over 50. All had a screw holding the MAP sensor. I just went out and checked the part number and 12602477 is found on the G8.
I looked up the 12590124 part number and it does come back with L76/L92, odd.
I looked up the 12590124 part number and it does come back with L76/L92, odd.
03-09-2015, 08:14 PM
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Performance wise, there is no difference or reason to care whether you have the LS3 intake manifold or the L76. Documentation indicates that the G8 GT from 2008-2009 had the L76 intake manifold and the G8 GXP in 2009 had the LS3 intake manifold. This may or may not prove true.
The only reason Peak Speed Shop has an interest in distinguishing between the two is that we carry cores and can offer core exchanges on the LS3 but not the L76. There isn't enough demand for the L76. If we didn't distinguish and a customer with the LS3 intake received a ported L76, their MAP sensor wouldn't be correct for mounting and vice versa. This thread is really for information purposes to those that want to be able to distinguish between the two.
The only reason Peak Speed Shop has an interest in distinguishing between the two is that we carry cores and can offer core exchanges on the LS3 but not the L76. There isn't enough demand for the L76. If we didn't distinguish and a customer with the LS3 intake received a ported L76, their MAP sensor wouldn't be correct for mounting and vice versa. This thread is really for information purposes to those that want to be able to distinguish between the two.
03-18-2015, 12:32 PM
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L76 intake manifold core available We just got in an L76 intake manifold in inventory. So, we can do a core exchange for anyone who wants their L76 intake manifold ported.
03-23-2021, 06:55 AM
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For the sake of bumping an old thread, the only other difference I've seen between the L76 vs LS3 intake manifolds not described are the mounting holes. The LS3 manifolds have a reinforced metal sleeve vs L76 just plastic (may crush if over torqued upon installation).
