Got this from a guy on TurboMustang. Good info if you are looking for a particular part number:
ALL Gen lll Engine's Gasket and Seals
#12574294 -Front Timing Cover Gasket
#12585673 -Front Timing Cover Crank Seal
#12574293 -Rear Cover Gasket
#89060436 -Rear Cover Main Seal
#12558760 -Valley Cover Gasket
#12558177 -Valley Cover Knock Sensor Seal SOLD AS A SINGLE
#12612045 -Valve Cover Gasket SOLD AS A SINGLE
#12577215 -Valve Cover Bolt with Groment SOLD AS A SINGLE
#12575329 -4.8L/5.3L GM MLS Head Gasket SOLD AS A SINGLE
#12498543 -LS1 5.7L GM Graphite Head Gasket 97-01 LS1/LS6 SOLD AS A SINGLE
#12498544 -LS1 5.3L HO/5.7L GM MLS Head gasket LS1 02-04/ 05-07 5.3L HO KIT W/ 2 HEAD GASKETS
#12589226 -LS1 5.3L HO/5.7L GM MLS Head gasket LS1 02-04/ 05-07 5.3L HO SOLD AS A SINGLE
#12589227 -6.0L GM MLS Head Gasket SAME for LQ4, LQ9, LS2 SOLD AS A SINGLE
#12582179 -LS7 GM MLS Head Gasket SOLD AS A SINGLE
#12610046 -LS3/L92 GM MLS Head Gasket SOLD AS A SINGLE
#12557752 -Oil Pump Pick up O ring w/o locator groove- GREEN in color WAS TOLD (C/K Trucks)
#12584922 -Oil Pump Pick up O ring w/ locator groove- RED in Color WAS TOLD (F and Y Cars)
#12482062 -Exahust Valve Seal SOLD AS A SINGLE
#12482063 -Intake Valve Seal SOLD AS A SINGLE
#12610311 -Water Pump Gasket SOLD AS A SINGLE
#89060413 -Truck Intake manifold Gaskets- W/ GREEN Seals
#12617944 -Exhaust Manifold gasket for Most V8 LS applications fits LS1, LS2, LS3, L76, and L92 SOLD AS A SINGLE
#12576221 -Exhaust Manifold gasket for the 2001 thru 2004 LS1 or LS6 Corvette. SOLD AS A SINGLE
#12587147 -Injector Seal Kit
#12552542 -Throttle Body Seal
#12551933 -Water tube cross over seal / block off seal SOLD AS A SINGLE
#12560251 -LS1-LS6 Intake gasket SOLD AS A SINGLE
#16194007 -Map Sensor Replacement Seal
#12482063 -L92 Valve Stem Seal Kit
#12558760 -L92 Oil Pan Gasket
#12610046 -L92 Head Gasket, 4.065" Bore SOLD AS A SINGLE
#12588372 -L92 Water Pump Gasket SOLD AS A SINGLE
#12556437 -L92 Camshaft Retainer w/ Seal
#12587099 -L92 Crankshaft Balancer Reverse Lip Seal
Gasket and Seal Kits
#12499228 -LS Series Engine Cam Swap Installation KIT The kit includes front engine cover gasket, water pump gasket, intake manifold gaskets, valve cover gaskets, balancer bolt, and front seal.
#12499217 -LS1 5.7L Cylinder Head Installation Kit The kit includes two head gaskets, two valve cover gaskets, eight manifold gaskets, two exhaust manifold gaskets, two intake manifold-to-block seals, 16 cylinder head bolts, and 14 cylinder head bolt/screws.
#89017252 -5.3L/4.8L Complete Head gasket kit
#12533587 -LS1-LS6 Intake Manifold Complete Seal KIT
#12499234 -LS1/LS6 Complete Piston Ring Set Standard Bore Size 3.898
#12499235 -5.3L/4.8L Complete Piston Ring Set 99-05 Standard BoreSize 3.78
#12499236 -6.0L LQ4/LQ9 Complete Piston Ring Set 99-05 Standard Bore Size 4.00
Sensors
#12601822 -Replacement Knock Sensor Harness for Truck
#12102621 -Just the Knock Sensor Connector Pig Tail
#12589867 -Knock Sensor SOLD AS A SINGLE
#16040609 -2 BAR MAP sensor
#12580698 -2 Bar MAP LSX engines
#12223861 -3 Bar sensor
#12561211 -CAM sensor LS1 ALL GEN 3 BASED MOTORS
#12560228 -CRANK sensor LS1 ALL GEN 3 BASED MOTORS
#16212460 -Map Sensor
#12570125 -L92 Knock Sensor SOLD AS A SINGLE
#12591720 -L92 Camshaft Position Sensor
#12585546 -L92 Crankshaft Position Sensor
#15326388 -L92 Engine Coolant Temperature Sensor
LS2 COILS HAVE 2 DESIGNS
#12573190 -ROUND SHAPED COILS
#12570616 -SQUARE SHAPED COILS
Internals/ External Part Numbers
#17122490 -GM LS7 Roller lifter This Number is for a single Lifter, They are packaged in sets of 8
#12499225 -GM LS7 Lifter Pack of 16 to 7000 RPM This is the number for a package of 16
#88958689 -GM High RPM Lifters Pack of 16 to 8000 RPM
#12586484 -Yellow Z06 Valve Spring Part number for 1 Spring
#12499224 -Yellow Z06 Valve Spring Set of 16 Springs
#10166344 -Retainer for all Factory springs SOLD AS A SINGLE
#10166345 -Keeper SOLD AS A SINGLE SET FOR ONE VALVE
#12551162 -Lifter Guide, LS1/LS6 SOLD AS A SINGLE
#12595365 -Lifter Guide, LS2/LS7 SOLD AS A SINGLE
#12551163 -Lifter Guide Bolt SOLD AS A SINGLE
#12569167 -L92 Intake Rocker Arm. SOLD AS A SINGLE
#10214664 -L92 Exhaust Rocker Arm. SOLD AS A SINGLE
#12600936 -L92 Rocker Arm Support Stand. SOLD AS A SINGLE
#12560961 -Rocker Arm Bolt for 4.8's, 5.3's, LS1, LS6, LS2, L76, and L92. Does NOT fit the LS7!
#12571595 -L92 Hydraulic Roller Two-Stage Valve Lifter [SOLD AS A SINGLE
#17122490 -L92 Hydraulic Roller Two-Stage Valve Lifter SOLD AS A SINGLE
#12571596 -L92 Front Lifter Guide SOLD AS A SINGLE
#12571608 -L92 Rear Lifter Guide SOLD AS A SINGLE
#89018058 -L92 spark plug wires
#12600767 -L92 Water pump
#12551926 -L92 Water Pump Bolt SOLD AS A SINGLE
#12587395 -L92Water Pump Inlet
#11516480 -L92 Water Pump Inlet Bolt SOLD AS A SINGLE
#12584727 -L92 Block
#12560272 -L92 Main Cap Bolt SOLD AS A SINGLE
#12560273 -L92 Main Cap Stud SOLD AS A SINGLE
#12556127 -L92 Main Cap Side Bolt SOLD AS A SINGLE
#12563918 -L92 Dipstick Tube
#12574888 -L92 Dipstick
#11519772 -L92 Long Cylinder Head Bolt M11 x 2 x 100 SOLD AS A SINGLE
#12558840 -L92 Short Cylinder Head Bolt M8 x 1.25 x 45 SOLD AS A SINGLE
#12590771 -L92 Intake Valve SOLD AS A SINGLE
#12582719 -L92 Exhaust Valve SOLD AS A SINGLE
#12557840 -L92 Crankshaft Balancer Bolt, M16 x 2.0 x 103
#12576652 -L92 Crankshaft Balancer
#12556582 -L92 Crankshaft Sprocket
#12561513 -L92 Crankshaft Key
#12584997 -L92 Crankshaft Assembly
#12602448 -L92 Flywheel
#12585994 -L92 Camshaft Position Actuator
#12588151 -L92 Camshaft Position Actuator Valve
#11561283 -L92 Camshaft Bolt, M16 x 1.5 x 63
#89018166 -Truck Water Pump
#89018053 -LS1, LS2, LS6 Water Pump
#89018052 -LS2, LS3 and LS7 Corvette Water Pump Only
#12586482 -GM HD Timing Chain
#12576407 -cam gear LS1- Trucks
#12586481 -cam gear LS2
#12556582 -crank gear
#12565308 -02-04 LS6 Cam
#12571251 -05-07 LS7 Cam
#12553118 -LS1 LS2 Balancer for car aplications
#12576652 -TRUCK Balancer for 4.8 5.3 6.0
#12557840 -Balancer bolt
#12586665 -OIL Pump
#12573460 -Rear Oil diverter W/Oring (AKA the Barbell in the back of the block)
#12560272 -Main Cap Bolt SOLD AS A SINGLE
#12560273 -Main Cap Bolt W/Stud for windage tray SOLD AS A SINGLE
#12556127 -Cross Bolts though the block into the side's of the main caps SOLD AS A SINGLE
#12570326 -Cylinder Head Dowl Locator SOLD AS A SINGLE
#89060420 -Fuel Presure Regulator Truck Return style fuel systems
#88862586 -EOS GM's Engine Assemebly Lube Oil Additive 1 Quart
#12559353 -24x Reluctor wheel
#12586768 -58x Reluctor wheel
#12563918 -Truck Dipstick Tube 99-07
#12558684 -Truck Dipstick 99-01
#12610053 -Truck Dipstick 02-07
#15203890 -HD OIL Cooler Line set 99-04
#12570623 -Oil Filler Tube
#89017365 -Truck Intake 4.8, 5.3, 6.0
#88894339 -LS6 Intake Manifold KIT w/o EGR This kit includes the intake manifold, intake seal P/N 12560251, intake manifold gasket kit P/N 12533587, throttle body seal P/N 12552542, map sensor P/N 16212460, map sensor seal P/N 16194007.
#12552344 -LS6 Intake manifold bolt SOLD AS A SINGLE
#12568002 -LS6 Valley Cover
#12573109 -LS6 Valley Cover pcv tube
#12554679 -Clip that hold the injectors to the fuel rail SOLD AS A SINGLE
#24500246 -Clip that holds the fuel regulator to the fuel rail SOLD AS A SINGLE
#12602448 -Standard Fly Wheel All LS1, LS2, LS3 engines To 4L60E/4L65E/4L70E
4L80E Conversion part numbers
#15000206 -Converter dust cover
#12551367 -6.0L Flexplate
#12563532 -6.0L Crank Spacer
#12553332 -Flexplate bolts SOLD AS A SINGLE (6 required)
#15198439 -4L80E Dipstick tube
#15183801 -4L80E Dipstick
#15013290 -4L80E Shift cable bracket at transmission
#11589040 -4L60/65/70/80/85E Toque converter bolt SOLD AS A SINGLE (6 required)
#15767858 -The transmission mount can be re-used because they use the same part number.
14 BOLT 9.5 SF Part Numbers
#3920486 -u-joint straps for 1350 U Joint SOLD AS A SINGLE (2 Required)
#14018700 -Strap Bolt SOLD AS A SINGLE (4 Required)
#19180849 -Axle Shaft Seal SOLD AS A SINGLE (2 Required)
#26064029 -Pinion Seal
#26063649 -Rear Diff Cover Gasket
#19133288 -Rear Diff Cover
#457108 -Inner Pinion bearing
#9417781 -Outer Pinion Bearing
#11505123 -Diff Side Bearing SOLD AS A SINGLE (2 Required)
#9439561 -Wheel Bearing SOLD AS A SINGLE (2 Required)
#12479321 -Carrier Gear kit W/O Limited Slip
#26060414 -Carrier Pin W/O Limited Slip
#12471409 -Carrier Gear kit W Limited Slip
#14012700 -Carrier Pin W Limited Slip
#12337937 -Gear side washer W/O Limited Slip
#14039026 -Pinion Washer W Limited Slip
#12471390 -Right Clutch for Limited Slip
#12471408 -Left Clutch for Limited Slip
This is what I found for Head Bolts.... 99-03... NOT sure on 04-UP Individual #'s
OK THERE ARE 3 DIFFERENT SIZE BOLTS.
#12558840 -SHORT...YOU NEED 10 Total
#12560745 -MED... YOU NEED 4 Total
#11588291 -LONG... YOU NEED 16 Total
Those are the totals needed to do Both heads.
From experince, I have found it is More expensive to get them individual through the dealer, then it is to get a Head bolt Kit from some one...
#12498545 -Should be a Head bolt Kit for 97-03 SOLD AS A SINGLE with the above 3 part numbers in it. YOU NEED 2 KITS
#17800568 -Should be a Head bolt Kit for 04-UP SOLD AS A SINGLE Not Sure On Individual part numbers. YOU NEED 2 KITS
GM Remanufactured LongBlock's
#12491851 - 4.8 LR4
#12491854 - 5.3 LM7/L59
#12491357 - 6.0 LQ4
#12491860 - 6.0 LQ9
ALL Gen lll Engine's Gasket and Seals
#12574294 -Front Timing Cover Gasket
#12585673 -Front Timing Cover Crank Seal
#12574293 -Rear Cover Gasket
#89060436 -Rear Cover Main Seal
#12558760 -Valley Cover Gasket
#12558177 -Valley Cover Knock Sensor Seal SOLD AS A SINGLE
#12612045 -Valve Cover Gasket SOLD AS A SINGLE
#12577215 -Valve Cover Bolt with Groment SOLD AS A SINGLE
#12575329 -4.8L/5.3L GM MLS Head Gasket SOLD AS A SINGLE
#12498543 -LS1 5.7L GM Graphite Head Gasket 97-01 LS1/LS6 SOLD AS A SINGLE
#12498544 -LS1 5.3L HO/5.7L GM MLS Head gasket LS1 02-04/ 05-07 5.3L HO KIT W/ 2 HEAD GASKETS
#12589226 -LS1 5.3L HO/5.7L GM MLS Head gasket LS1 02-04/ 05-07 5.3L HO SOLD AS A SINGLE
#12589227 -6.0L GM MLS Head Gasket SAME for LQ4, LQ9, LS2 SOLD AS A SINGLE
#12582179 -LS7 GM MLS Head Gasket SOLD AS A SINGLE
#12610046 -LS3/L92 GM MLS Head Gasket SOLD AS A SINGLE
#12557752 -Oil Pump Pick up O ring w/o locator groove- GREEN in color WAS TOLD (C/K Trucks)
#12584922 -Oil Pump Pick up O ring w/ locator groove- RED in Color WAS TOLD (F and Y Cars)
#12482062 -Exahust Valve Seal SOLD AS A SINGLE
#12482063 -Intake Valve Seal SOLD AS A SINGLE
#12610311 -Water Pump Gasket SOLD AS A SINGLE
#89060413 -Truck Intake manifold Gaskets- W/ GREEN Seals
#12617944 -Exhaust Manifold gasket for Most V8 LS applications fits LS1, LS2, LS3, L76, and L92 SOLD AS A SINGLE
#12576221 -Exhaust Manifold gasket for the 2001 thru 2004 LS1 or LS6 Corvette. SOLD AS A SINGLE
#12587147 -Injector Seal Kit
#12552542 -Throttle Body Seal
#12551933 -Water tube cross over seal / block off seal SOLD AS A SINGLE
#12560251 -LS1-LS6 Intake gasket SOLD AS A SINGLE
#16194007 -Map Sensor Replacement Seal
#12482063 -L92 Valve Stem Seal Kit
#12558760 -L92 Oil Pan Gasket
#12610046 -L92 Head Gasket, 4.065" Bore SOLD AS A SINGLE
#12588372 -L92 Water Pump Gasket SOLD AS A SINGLE
#12556437 -L92 Camshaft Retainer w/ Seal
#12587099 -L92 Crankshaft Balancer Reverse Lip Seal
Gasket and Seal Kits
#12499228 -LS Series Engine Cam Swap Installation KIT The kit includes front engine cover gasket, water pump gasket, intake manifold gaskets, valve cover gaskets, balancer bolt, and front seal.
#12499217 -LS1 5.7L Cylinder Head Installation Kit The kit includes two head gaskets, two valve cover gaskets, eight manifold gaskets, two exhaust manifold gaskets, two intake manifold-to-block seals, 16 cylinder head bolts, and 14 cylinder head bolt/screws.
#89017252 -5.3L/4.8L Complete Head gasket kit
#12533587 -LS1-LS6 Intake Manifold Complete Seal KIT
#12499234 -LS1/LS6 Complete Piston Ring Set Standard Bore Size 3.898
#12499235 -5.3L/4.8L Complete Piston Ring Set 99-05 Standard BoreSize 3.78
#12499236 -6.0L LQ4/LQ9 Complete Piston Ring Set 99-05 Standard Bore Size 4.00
Sensors
#12601822 -Replacement Knock Sensor Harness for Truck
#12102621 -Just the Knock Sensor Connector Pig Tail
#12589867 -Knock Sensor SOLD AS A SINGLE
#16040609 -2 BAR MAP sensor
#12580698 -2 Bar MAP LSX engines
#12223861 -3 Bar sensor
#12561211 -CAM sensor LS1 ALL GEN 3 BASED MOTORS
#12560228 -CRANK sensor LS1 ALL GEN 3 BASED MOTORS
#16212460 -Map Sensor
#12570125 -L92 Knock Sensor SOLD AS A SINGLE
#12591720 -L92 Camshaft Position Sensor
#12585546 -L92 Crankshaft Position Sensor
#15326388 -L92 Engine Coolant Temperature Sensor
LS2 COILS HAVE 2 DESIGNS
#12573190 -ROUND SHAPED COILS
#12570616 -SQUARE SHAPED COILS
Internals/ External Part Numbers
#17122490 -GM LS7 Roller lifter This Number is for a single Lifter, They are packaged in sets of 8
#12499225 -GM LS7 Lifter Pack of 16 to 7000 RPM This is the number for a package of 16
#88958689 -GM High RPM Lifters Pack of 16 to 8000 RPM
#12586484 -Yellow Z06 Valve Spring Part number for 1 Spring
#12499224 -Yellow Z06 Valve Spring Set of 16 Springs
#10166344 -Retainer for all Factory springs SOLD AS A SINGLE
#10166345 -Keeper SOLD AS A SINGLE SET FOR ONE VALVE
#12551162 -Lifter Guide, LS1/LS6 SOLD AS A SINGLE
#12595365 -Lifter Guide, LS2/LS7 SOLD AS A SINGLE
#12551163 -Lifter Guide Bolt SOLD AS A SINGLE
#12569167 -L92 Intake Rocker Arm. SOLD AS A SINGLE
#10214664 -L92 Exhaust Rocker Arm. SOLD AS A SINGLE
#12600936 -L92 Rocker Arm Support Stand. SOLD AS A SINGLE
#12560961 -Rocker Arm Bolt for 4.8's, 5.3's, LS1, LS6, LS2, L76, and L92. Does NOT fit the LS7!
#12571595 -L92 Hydraulic Roller Two-Stage Valve Lifter [SOLD AS A SINGLE
#17122490 -L92 Hydraulic Roller Two-Stage Valve Lifter SOLD AS A SINGLE
#12571596 -L92 Front Lifter Guide SOLD AS A SINGLE
#12571608 -L92 Rear Lifter Guide SOLD AS A SINGLE
#89018058 -L92 spark plug wires
#12600767 -L92 Water pump
#12551926 -L92 Water Pump Bolt SOLD AS A SINGLE
#12587395 -L92Water Pump Inlet
#11516480 -L92 Water Pump Inlet Bolt SOLD AS A SINGLE
#12584727 -L92 Block
#12560272 -L92 Main Cap Bolt SOLD AS A SINGLE
#12560273 -L92 Main Cap Stud SOLD AS A SINGLE
#12556127 -L92 Main Cap Side Bolt SOLD AS A SINGLE
#12563918 -L92 Dipstick Tube
#12574888 -L92 Dipstick
#11519772 -L92 Long Cylinder Head Bolt M11 x 2 x 100 SOLD AS A SINGLE
#12558840 -L92 Short Cylinder Head Bolt M8 x 1.25 x 45 SOLD AS A SINGLE
#12590771 -L92 Intake Valve SOLD AS A SINGLE
#12582719 -L92 Exhaust Valve SOLD AS A SINGLE
#12557840 -L92 Crankshaft Balancer Bolt, M16 x 2.0 x 103
#12576652 -L92 Crankshaft Balancer
#12556582 -L92 Crankshaft Sprocket
#12561513 -L92 Crankshaft Key
#12584997 -L92 Crankshaft Assembly
#12602448 -L92 Flywheel
#12585994 -L92 Camshaft Position Actuator
#12588151 -L92 Camshaft Position Actuator Valve
#11561283 -L92 Camshaft Bolt, M16 x 1.5 x 63
#89018166 -Truck Water Pump
#89018053 -LS1, LS2, LS6 Water Pump
#89018052 -LS2, LS3 and LS7 Corvette Water Pump Only
#12586482 -GM HD Timing Chain
#12576407 -cam gear LS1- Trucks
#12586481 -cam gear LS2
#12556582 -crank gear
#12565308 -02-04 LS6 Cam
#12571251 -05-07 LS7 Cam
#12553118 -LS1 LS2 Balancer for car aplications
#12576652 -TRUCK Balancer for 4.8 5.3 6.0
#12557840 -Balancer bolt
#12586665 -OIL Pump
#12573460 -Rear Oil diverter W/Oring (AKA the Barbell in the back of the block)
#12560272 -Main Cap Bolt SOLD AS A SINGLE
#12560273 -Main Cap Bolt W/Stud for windage tray SOLD AS A SINGLE
#12556127 -Cross Bolts though the block into the side's of the main caps SOLD AS A SINGLE
#12570326 -Cylinder Head Dowl Locator SOLD AS A SINGLE
#89060420 -Fuel Presure Regulator Truck Return style fuel systems
#88862586 -EOS GM's Engine Assemebly Lube Oil Additive 1 Quart
#12559353 -24x Reluctor wheel
#12586768 -58x Reluctor wheel
#12563918 -Truck Dipstick Tube 99-07
#12558684 -Truck Dipstick 99-01
#12610053 -Truck Dipstick 02-07
#15203890 -HD OIL Cooler Line set 99-04
#12570623 -Oil Filler Tube
#89017365 -Truck Intake 4.8, 5.3, 6.0
#88894339 -LS6 Intake Manifold KIT w/o EGR This kit includes the intake manifold, intake seal P/N 12560251, intake manifold gasket kit P/N 12533587, throttle body seal P/N 12552542, map sensor P/N 16212460, map sensor seal P/N 16194007.
#12552344 -LS6 Intake manifold bolt SOLD AS A SINGLE
#12568002 -LS6 Valley Cover
#12573109 -LS6 Valley Cover pcv tube
#12554679 -Clip that hold the injectors to the fuel rail SOLD AS A SINGLE
#24500246 -Clip that holds the fuel regulator to the fuel rail SOLD AS A SINGLE
#12602448 -Standard Fly Wheel All LS1, LS2, LS3 engines To 4L60E/4L65E/4L70E
4L80E Conversion part numbers
#15000206 -Converter dust cover
#12551367 -6.0L Flexplate
#12563532 -6.0L Crank Spacer
#12553332 -Flexplate bolts SOLD AS A SINGLE (6 required)
#15198439 -4L80E Dipstick tube
#15183801 -4L80E Dipstick
#15013290 -4L80E Shift cable bracket at transmission
#11589040 -4L60/65/70/80/85E Toque converter bolt SOLD AS A SINGLE (6 required)
#15767858 -The transmission mount can be re-used because they use the same part number.
14 BOLT 9.5 SF Part Numbers
#3920486 -u-joint straps for 1350 U Joint SOLD AS A SINGLE (2 Required)
#14018700 -Strap Bolt SOLD AS A SINGLE (4 Required)
#19180849 -Axle Shaft Seal SOLD AS A SINGLE (2 Required)
#26064029 -Pinion Seal
#26063649 -Rear Diff Cover Gasket
#19133288 -Rear Diff Cover
#457108 -Inner Pinion bearing
#9417781 -Outer Pinion Bearing
#11505123 -Diff Side Bearing SOLD AS A SINGLE (2 Required)
#9439561 -Wheel Bearing SOLD AS A SINGLE (2 Required)
#12479321 -Carrier Gear kit W/O Limited Slip
#26060414 -Carrier Pin W/O Limited Slip
#12471409 -Carrier Gear kit W Limited Slip
#14012700 -Carrier Pin W Limited Slip
#12337937 -Gear side washer W/O Limited Slip
#14039026 -Pinion Washer W Limited Slip
#12471390 -Right Clutch for Limited Slip
#12471408 -Left Clutch for Limited Slip
This is what I found for Head Bolts.... 99-03... NOT sure on 04-UP Individual #'s
OK THERE ARE 3 DIFFERENT SIZE BOLTS.
#12558840 -SHORT...YOU NEED 10 Total
#12560745 -MED... YOU NEED 4 Total
#11588291 -LONG... YOU NEED 16 Total
Those are the totals needed to do Both heads.
From experince, I have found it is More expensive to get them individual through the dealer, then it is to get a Head bolt Kit from some one...
#12498545 -Should be a Head bolt Kit for 97-03 SOLD AS A SINGLE with the above 3 part numbers in it. YOU NEED 2 KITS
#17800568 -Should be a Head bolt Kit for 04-UP SOLD AS A SINGLE Not Sure On Individual part numbers. YOU NEED 2 KITS
GM Remanufactured LongBlock's
#12491851 - 4.8 LR4
#12491854 - 5.3 LM7/L59
#12491357 - 6.0 LQ4
#12491860 - 6.0 LQ9