Hello This auction is for a new pair,(2) Pro header LS cylinder heads for LS3 LS7 CHEVROLET ENGINES. Heads have huge square 
291cc intake runners and 69cc combustion chambers. These Heads are much better than stock GM heads, you will get easily 75-80hp gains or more!! These are new head castings that WE CNC Machine and assemble, that is why and how we have no issues!!, bolt on performance and reliability!. Heads are Brand new and all components are brand new parts. Please look close at all the pictures you can see we do all CNC Machine work in house!! with expert people who assemble the heads for trouble free service. Heads have all bolts holes for all stock accessory brackets, no special brackets needed,  no special intakes or exhaust needed, run Stock stuff or aftermarket  parts with no problems and great performance!!. These heads fit all GM blocks, they are a great replacement for stock heads in your Z06 Corvette or any vehicle with an LS7/LS3 block.
 All specs are listed as follows,

Chevy LS3 LS7 291cc 69cc Assembled Aluminum Cylinder Heads



Part Type:Cylinder Heads
  
Cylinder Head Style:Assembled
Cylinder Head Material:Aluminum
Cylinder Head Finish:Natural
Combustion Chamber Volume (cc):69 cc
CNC-Machined Combustion Chamber:No
Intake Runner Volume (cc): 
291 cc 
 
CNC-Machined Intake Runner: No
CNC-Machined Exhaust Runner: No
Intake Port Shape: Square
Intake Port Location: Standard
Exhaust Port Shape: Oval
Exhaust Port Location: Standard
Comp. Valve Job: 

Seat Pressures:

Seat Pressure W/O Inner Spring:		Yes 

Closed 150

Closed 120
Intake Valves Included: Yes
Intake Valve Diameter (in): 2.200 in.
Exhaust Valves Included: Yes
Exhaust Valve Diameter (in): 1.615 in. 
Valve Springs Included:  Yes (Double Springs up to .680 lift) 
Retainers Included: Yes
Locks Included: Yes
Valve Stem Seals Included: Yes 
Rocker Arm Studs Included: No 
Rocker Arms Included: No 
Rocker Arm Nuts Included: No 
Guideplates Included: No 
Valve Cover Mounting Style: Perimeter Bolt
Accessory Bolt Holes Drilled: Yes 
Intake Valve Angle:  deg.
Exhaust Valve Angle:  deg.
Valve Guides Included: Yes 
Valve Guide Material: Ductile iron 
Valve Seats Machined: Yes
Valve Seat Machine Style: 3-angle
Valve Seat Material: Ductile iron 
Oiling Style: Through pushrod 
Machined for O-Ring: No 
Heat Crossover: No
Quantity:Sold in Sets of Two
Parts Used in Assembly as follows: 
  • 1.615" one piece swirl polished stainless steel severe duty exhaust valves (Qualcast)
  • 2.200" one piece swirl polished stainless steel severe duty intake valves (Qualcast)
  • 1.320" OD X 2.235 True Double Springs  (Qualcast)
  • New Hardened 1.300 Retainers 7°
  • New Hardened 312 Valve Locks
  • New 312  Positive Control Seals
  • New .015" Valve Shim
  • Springs,
    Engine: LS3/LS7
    Number Of Coils: Dual Spring
    Damper Spring: No
    Overall Diameter: 1.320" OD
    Inside Diameter: .676" ID
    Spring Height: 1.800"
    Seat Pressure: 150 lbs @ 1.800"
    Open Pressure: 395 lbs. @ 1.150"
    Coil Bind: 1.100"
    Spring Rate (lbs./in.): 375 lbs/in
    Max Lift: .680"

The LS7 heads are only compatible with LS3 blocks when the bore is 4.000" or larger. Please check your bore sizes on LS3 applications before purchasing.
These heads are assembled and have 150 pounds closed seat pressure. If that is too much you can remove the inner spring and that will put you at 120 Pounds closed seat pressure which is more for a stock replacement. No beehive springs here!!  We  do the CNC maching and assembly. These heads are comparable to Dart world AFR speedmaster pro comp Edelbrock GM. Thanks for looking

Please feel free to ask any and all questions directly thru ebay messaging system, I will answer all questions, I want you happy!!. I cant include personal contact information its against ebay policy, After purchase on ebay we can exchange contact information as needed.