LS2 vs LS3
Thread Starter
Race Director
Joined: Oct 1999
Posts: 13,298
Likes: 14
From: Somers NY
I'm happy with the LS3 so far. I got a 11.94 a couple of weeks ago at E-town's Wednesday night Test and Tune. Was only able to run twice that night. This is with a Vararam and tune. Still running Goodyear run flats and traction control ON. Don't know what to do or how to run it next. Was going to mod my car with things that is working for you John. But, your doing mods faster than I want. 
I plan on going to E Town next Sat (Oct 18) to see how it runs on the DR's
It seems like you are definitely faster with the LS3 than my LS2 .. The converter won't go on until the winter (I Hope)
Premium Supporting Vendor
Joined: Oct 2005
Posts: 13,975
Likes: 980
From: Clinton Township MI
C7 of Year Finalist (track prepared) 2019
LS7 is CNC ported from the factory, LS3 is as-cast
LS7 intake port height is different
LS7 has an offset intake rocker
LS7 has a 12 degree valve angle, LS3 has 15 degrees
LS7 valves are 2.200/1.610 Titanium intake/Hollow stem, sodium-filled stainless steel exhaust. LS3 are 2.165/1.590 Hollow stem stainless steel intake/Solid stainless steel exhaust
LS7 has 70cc combustion chamber, LS3 has 68.7
LS6 and LS2 valve sizes are the same, but the LS6 has hollow stem valves, sodium filled on the exhaust
All-new aluminum block casting incorporates provisions for external knock sensors and revised oil galleries; external sensors improve serviceability
Cylinder bore diameter increased to 101.6 mm (4.00 inches), increasing displacement to 6.0 liters
Camshaft lift increased to take advantage of increased cylinder head flow
Camshaft sensor relocated from the rear of the block to the front of the block provides room for new oil galleries
Flat-top piston design with lower ring tension reduces friction
Piston floating wrist pins help quiet the engine
Redesigned, “wingless” oil pan with cast baffling has reduced mass and provides superior oil control under high-performance driving maneuvers
Revised exhaust manifolds are 33 percent lighter
More efficient ignition coils require less energy to provide a comparable spark
Compression raised to 10.9:1
Larger, 90-mm single-blade throttle body
Reduced-mass water pump design with improved sealing capability
Engine redline raised to 6500 rpm
Revised and more powerful engine controller incorporates all electronic throttle control functions.
Le Mans Master
Joined: Dec 2005
Posts: 6,999
Likes: 1,684
From: Southeast TX
The LS3 and LS7 heads are not the same.
LS7 is CNC ported from the factory, LS3 is as-cast
LS7 intake port height is different
LS7 has an offset intake rocker
LS7 has a 12 degree valve angle, LS3 has 15 degrees
LS7 valves are 2.200/1.610 Titanium intake/Hollow stem, sodium-filled stainless steel exhaust. LS3 are 2.165/1.590 Hollow stem stainless steel intake/Solid stainless steel exhaust
LS7 has 70cc combustion chamber, LS3 has 68.7
Yes, LS2 and LS6 heads are 243 castings.
LS6 and LS2 valve sizes are the same, but the LS6 has hollow stem valves, sodium filled on the exhaust
The LS2 is more similar to the LS6 than it is to the LS3, but there are some differences. Going from the LS6 to the LS2:
All-new aluminum block casting incorporates provisions for external knock sensors and revised oil galleries; external sensors improve serviceability
Cylinder bore diameter increased to 101.6 mm (4.00 inches), increasing displacement to 6.0 liters
Camshaft lift increased to take advantage of increased cylinder head flow
Camshaft sensor relocated from the rear of the block to the front of the block provides room for new oil galleries
Flat-top piston design with lower ring tension reduces friction
Piston floating wrist pins help quiet the engine
Redesigned, “wingless” oil pan with cast baffling has reduced mass and provides superior oil control under high-performance driving maneuvers
Revised exhaust manifolds are 33 percent lighter
More efficient ignition coils require less energy to provide a comparable spark
Compression raised to 10.9:1
Larger, 90-mm single-blade throttle body
Reduced-mass water pump design with improved sealing capability
Engine redline raised to 6500 rpm
Revised and more powerful engine controller incorporates all electronic throttle control functions.
LS7 is CNC ported from the factory, LS3 is as-cast
LS7 intake port height is different
LS7 has an offset intake rocker
LS7 has a 12 degree valve angle, LS3 has 15 degrees
LS7 valves are 2.200/1.610 Titanium intake/Hollow stem, sodium-filled stainless steel exhaust. LS3 are 2.165/1.590 Hollow stem stainless steel intake/Solid stainless steel exhaust
LS7 has 70cc combustion chamber, LS3 has 68.7
Yes, LS2 and LS6 heads are 243 castings.
LS6 and LS2 valve sizes are the same, but the LS6 has hollow stem valves, sodium filled on the exhaust
The LS2 is more similar to the LS6 than it is to the LS3, but there are some differences. Going from the LS6 to the LS2:
All-new aluminum block casting incorporates provisions for external knock sensors and revised oil galleries; external sensors improve serviceability
Cylinder bore diameter increased to 101.6 mm (4.00 inches), increasing displacement to 6.0 liters
Camshaft lift increased to take advantage of increased cylinder head flow
Camshaft sensor relocated from the rear of the block to the front of the block provides room for new oil galleries
Flat-top piston design with lower ring tension reduces friction
Piston floating wrist pins help quiet the engine
Redesigned, “wingless” oil pan with cast baffling has reduced mass and provides superior oil control under high-performance driving maneuvers
Revised exhaust manifolds are 33 percent lighter
More efficient ignition coils require less energy to provide a comparable spark
Compression raised to 10.9:1
Larger, 90-mm single-blade throttle body
Reduced-mass water pump design with improved sealing capability
Engine redline raised to 6500 rpm
Revised and more powerful engine controller incorporates all electronic throttle control functions.
