BLOCKS  HEADS 
CAMSHAFTS FRONT DRIVES 
OIL PANS  WATER PUMPS 
BALANCERS  VALVE COVERS 
INTAKE MANIFOLDS   

 

LS BASED GEN III DISPLACEMENT INFORMATION
RPO VOL CID CR BORE STROKE BLOCK OE APPLICATIONS
LS1 5.7L 346 10.2:1 3.898" 3.622" ALUM 97-04 Corvette, 98-02 Camaro/Firebird, 04 GTO
LS2 6.0L 364 10.5:1 4.000" 3.622" ALUM 05-07 Corvette, 05-06 GTO, 07 CTS-V
LS3 6.2L 376 10.7:1 4.065" 3.622" ALUM 08-09 Corvette
LS6 5.7L 346 10.5:1 3.898" 3.622" ALUM 02-05 Corvette Z06, 04-05 CTS-V
LS7 7.0L 427 11.0:1 4.125" 4.000" ALUM 07-09 Corvette Z06
LS9 6.2L 376 9.1:1 4.065" 3.622 ALUM 09 Corvette ZR1 (Supercharged)
L92 6.2L 376 10.7:1 4.065" 3.622" ALUM 07-11 Escalade, 10-11 Silverado/Sierra, 07-11 Yukon Denali, 08 Hummer H2
LQ4 6.0L 364 9.4:1 4.000" 3.622" IRON 99-Present Full-Size Trucks
LQ9 6.0L 364 10.1:1 4.000" 3.622" IRON Escalade, Silverado SS, Full-Size Trucks
LM4 5.3L 325 9.5:1 3.780" 3.622" ALUM 04-Present Full Size Trucks, 04 SSR/Trailblazer/Envoy/Bravada
LM7 5.3L 325 9.5:1 3.780" 3.622" IRON 99-Present Full Size Trucks
LR4 4.8L 293 9.5:1 3.780" 3.267" IRON 99-Present Full Size Trucks
LSA 6.2L 376 9.0:1 4.065" 3.622" ALUM 2009-2011 CTS-V, 2012 Camaro ZL1

All LS based engines have a 9.240 Deck height, unless it's an LSX block, which is available in a 9.26" and a 9.70" deck

 

 

LS SERIES CRANKSHAFT RELUCTORS AND SENSORS
LS based motors use 2 different reluctor rings and sensors (24x and 58x).  There are also 3 different bolt patterns for the flywheel/flexplate : 6-bolt (all LS), 8-bolt (LSA) and 9-bolt (LS9).  Proper orientation of the crank ring is required if switching the reluctors.  Below are photos of the orientation of the rings.  You will notice on both rings, there are triangular/arrowed windows that align with 2 bolt holes, and the non-windowed portions of the ring cover the crankshaft throw weights.  A 24x pickup ring uses a black colored crankshaft sensor, a 58x pickup ring uses a gray colored crankshaft sensor.  The connectors are also differently keyed between the 2 sensors. You cannot use a 24x sensor on a 58x crank to convert to 24x (or vice versa). The crankshaft pickup count must match the type of ECM you are using, so if you are using a 24x ECM, then you install all 24x components.
 
24x reluctor 58x reluctor 24x crank sensor 58x crank sensor
 

 

LS CAMSHAFT SPECFICATIONS 
CASTING # MAKE/MODEL BOLTS/PICKUP INT EXH INT EXH LSA
12554710 97-99 CORVETTE, 98-99 F-BODY LS1 3 w/ PU 202 210 .496 .496 116
12560964 99 CORVETTE LS1 3 w/ PU 199 207 .479 .472 117
12557812/12560965 98-00 CORVETTE LS1/ F-BODY LS1 3 w/ PU 198 209 .500 .500 119.5
12561721 01-02 F-BODY LS1/01-04 LQ9 3 w/ PU 197 207 .467 .479 116
12560950 01 CORVETTE Z06 LS6/05-07 LS2 3 w/ PU 207 217 .525 .525 116
12565308 02-04 CORVETTE Z06 LS6 3 w/ PU 204 218 .551 .547 117
12560967 99-04 5.3 LM7/99-00 LQ4 3 w/ PU 190 191 .466 .457 114
12571251 05-10 LS7 3 w/o PU 211 230 .593 .588  
88958733 GM PERFORMANCE HOT CAM 3 w/ PU 218 227 .525 .525 112
12480110 GM PERFORMANCE ASA CAM 3 w/ PU 226 236 .525 .525 110
12623083 08-09 LS3 CAM 1 w/o PU 204 211 .551 .522 117

LS based engines use 1.7:1 ratio rocker arms, LS7 engines use 1.8:1 ratio rocker arms

 

LS GEN III SMALL BLOCK CHEVROLET CYLINDER HEAD CASTING #'S
CASTING # USAGE PORT YEAR CID CC INT EXH MAT
10215339 LS1 CATHEDRAL 97 CORVETTE 346 67 200 70 AL
12556743   CATHEDRAL 99 TRUCKS 325 61 200 70 AL
12558806 LS1 CATHEDRAL 97-98 CORVETTE/F-BODY 346 68 200 70 AL
12559863 LS1 CATHEDRAL 99-02 CORVETTE/F-BODY 346 68 200 70 AL
12559853 LS1 CATHEDRAL 99-02 CORVETTE/F-BODY 346 68 200 70 AL
12559862   CATHEDRAL 99-00 TRUCKS 287/325 61 200 70 AL
12559895   CATHEDRAL 00-07 TRUCKS 325 61 200 70 AL
12561706   CATHEDRAL 01-04 TRUCKS 325 61 200 70 AL
12561873   CATHEDRAL 99-01 TRUCKS 364 71 210 75 CI
12562317 LQ4 CATHEDRAL 01-04 TRUCKS 364 71 210 75 AL
12564241 LS1 CATHEDRAL 00-04 CORVETTE/00-02 F-BODY 346 68 200 70 AL
12564243 LS6/LS2 CATHEDRAL 01-04 CORVETTE/ 04-06 GTO 346/364 65 210 75 AL
12572035   CATHEDRAL 01-04 364 71 210 75 AL
LEGEND

AL = ALUMINUM HEADS, CI = CAST IRON HEADS

 

LS SERIES GEN III INTAKE MANIFOLDS

USAGE CASTING # PORT TBI EGR FUEL RAIL
           
98-00 F-BODY 12560688 CATHEDRAL 3-BOLT YES LS1/LS6 (UP TO 2004)
97-00 CORVETTE 12556333 CATHEDRAL 3-BOLT NO LS1/LS6 (UP TO 2004)
01-04 CORVETTE 12561182 CATHEDRAL 3-BOLT NO LS1/LS6 (UP TO 2004)
01-02 F-BODY/01-04 CORVETTE 12563572 CATHEDRAL 3-BOLT NO LS1/LS6 (UP TO 2004)
05-07 LS2 CORVETTE/GTO/CTS-V 12589181 CATHEDRAL 4-BOLT NO LS2
LS3 1ST DESIGN (CLIP IN MAP)     4-BOLT NO  
LS3 2ND DESIGN (BOLT IN MAP)     4-BOLT NO  
LS7 1ST DESIGN (CLIP IN MAP) 12560911 LS7 4-BOLT NO LS7 ONLY
TRUCK INTAKE 25321788        
TRUCK INTAKE 12573944        
TRUCK INTAKE 12574009        
TRAILBLAZER SS 25379707 CATHEDRAL 4-BOLT NO TRUCK ONLY
           
     
     There were many different intakes used on the LS series motors.  There are designs for each head style : cathedral port (LS1/LS2/LS6/4.8/5.3/6.0), rectangular port (LS3/L92)  and LS7.   There are also different style height intakes : car platform and truck platforms.  You can interchange intakes as long as you use the same cylinder head design, and use the corresponding fuel rails, injectors and throttle bodies (as certain models have different bolt patterns).
 
THROTTLE BODY DIFFERENCES 
  • There are 2 different mechanical throttle body arms.  The photo on the left is the short arm, it can be easily recognized from the round collar.  The photo on the right is the long arm, and the collar is straight.  You must use either an adjustable throttle cable, or a throttle cable specific to that throttle body for the throttle to open properly. 
  • There are also 2 basic throttle bodies : car and truck.  The difference is the coolant passage for water pump clearance and the breather hose angle (for throttle bracket clearance)
   

 

FUEL INJECTORS
 
 
INJECTOR LENGTH* CONNECTOR
TPI 2.5" EV1
LT1 2.6" EV1
LS1/LS6 2.5" EV1
LS2 2.1" EV6
LS3/LS7/LS9/L76 1.5" EV6
VORTEC TRUCK 1.9" EV6
* Injector length is measured from o-ring to o-ring

 

LS SERIES III VALVE COVER BOLT PATTERNS

 

Although there are many different valve covers for many different applications, there are basically 2 different valve covers : perimeter bolt valve covers, and center bolt valve covers.  The perimeter bolt valve covers were used on 97-98 Corvettes and 98 Camaros and Firebirds.  All other models used the center bolt valve covers.  On the perimeter bolt valve covers, the ignition coils bolt directly to the valve cover.  On the center bolt valve covers, the ignition coils bolt to a bracket, which in turn bolts to the valve cover.  This is to facilitate the removal of the valve cover when necessary.

 

LS SERIES III VALVE COVER BREATHER DIFFERENCES

   

There are many different model valve covers, all specific to each application, but for swap purposes, you can get around having the exact cover.  All the LS models have the oil filler on the passenger valve cover (except LS7).  Breather locations (the small tubes on the outside of the covers) differ between models for intake purposes, however, they are all just breathers.

 

LS SERIES GEN III FRONT DRIVE CONFIGURATIONS

     
98-02 LS1 CAMARO & FIREBIRD 97-04 LS1/LS6 CORVETTE  04-06 LS6 CTS-V 
     
04-06 LS1/LS2 GTO  99-07 4.8/5.3/6.0 TRUCK  05-07 LS2/LS7 CORVETTE

 

LS SERIES GEN III HARMONIC BALANCERS


 

     There are basically 3 different harmonic balancers that effect belt spacing : (1) Corvette and Cadillac (car), (2) Camaro/Firebird and GTO, (3) Truck series and SUV.  As you can clearly see, the distance between the crankshaft end and where the belt rides are different in all 3.  All of the LS based balancers are neutral balanced, and can be installed on any LS application as long as the same platform accessories are used.

 

 
LS SERIES GEN III WATER PUMP PULLEY DRIVE LOCATIONS

     

     The Corvette, Camaro, Firebird and GTO all share the same water pump, even though they use different depth balancers.  The reason the water pumps are interchangeable is that the water pump drive pulley is twice as wide as the other platforms, allowing the belt to ride in 2 different locations.  Therefore, you can use either water pump with either platform, although you should check your clearance between your fans and/or radiator.  04 and later model Corvette platforms use a water pump that has the pulley only as wide as the belt.

   

 

LS SERIES GEN III WATER PUMP SNOUT DIFFERENCES

     

     The snouts are different on car platforms VS truck/SUV platforms due to the mechanically driven fan.  The truck/SUV pumps are extended forward, closer to the radiator VS the car platforms, also the pulley is not as wide as they only use 1 style balancer.  The truck/SUV balancer also has provision for the mechanical fan, which screw on the snout.  The car applications all use electrical fans therefore you will need to install an electrical fan if doing a swap.

 

LS SERIES GEN III WATER PUMP OUTLET DIFFERENCES

   

     Car platforms and truck/SUV platforms have the water outlet in a different location.  Since the car platforms have a lower intake, the water outlet is parallel to the drive pulley.  On truck platforms, the outlet is perpendicular to the drive pulley.  Also, all truck/SUV applications use a closed coolant system with a surge tank, so if you use a truck/SUV water pump, be sure your water levels are above the hose,

 

LS SERIES GEN III WATER PUMP OUTLET DIFFERENCES

   
 97-03 model water  pumps have the thermostat as part of the thermostat housing, and is not removable (at least not by hand).  This style uses a large O-ring to seal the housing to the pump.  04-present water pumps have a thermostat that has a separate housing, and the thermostat easily slides out.  The O-ring on this model is part of the thermostat.  Another visual difference is in the casting.  The 97-03 housings have an additional tab on it to hold the wiring in place for the A/C compressor.  The 04-present models do not have that tab.  The housings are not interchangeable between pumps since the diameter of the thermostat cavity is different and the bolt pattern for the housing is different.

***NOTE : GM water pumps sold after 2005 all have the 2-piece design, meaning if you ordered a new GM water pump for your 1998 Corvette, it came with the newer 2-piece thermostat.
LS SERIES GEN III  OIL PANS 
All LSx oil pans are interchangeable, pending you swap the corresponding windage (deflector) tray and pickup tubes along with the pan.  The windage trays and pickup tubes are specific to the oil pan.  All oil feeds are on the LH side of the block, if there's an oil filter on the RH side, the oil pan transfer's the oil to the LH side of the block via piping.

   

   

   

Holley LSx Swap Oil Pan  
 

 

OTHER LSX DIFFERENCES

  There were 2 different style knock sensors offered on Gen III LSx engines : A locking tab design, and a standard style connector (same as TPI and LT1 style knock sensor connectors).  The locking tab was on all 1997 LS1 engines, and in most (but not all) 1998 LS1 engines.  The only way to know what you have is to pull the intake off.  You can use either sensor in either block, as long as you have the matching knock harness.

 

LSx OIL AND COOLANT PLUG LOCATIONS
     The LS series engines have alot of strange looking plugs compared to the normal small block chevrolet engine.  Below is a small set of photos outlining the plugs and their locations.