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F715 294cc LS7 Square Cylinder Heads (set) - HR - Complete

! WARNING: Cancer and Reproductive Harm -

Starting at $3999

Set of two (2) LS7 square port cylinder heads. Heads are complete and assembled. Valve covers, oil fill cap, and doweled rocker stands included with purchase.

  • 15° valve angle
  • Solid, stainless 2.200” intake / 1.650” exhaust valves
  • 4.125” minimum bore size
  • FED titanium 0.660” lift Spring Kit
  •  ¼” NPT water crossover ports
  • 294cc equivalent.
  • 100% Designed, Tooled, Cast and Machined in the USA.
  • A357 T6 Aluminum Castings – T6 heat treated, low silica alloy. Similar in strength, machine-ability and weld-ability to 6061-T6 billet. Superior strength compared to all commercially available castings. 20% stronger than similar high-end castings made from A356. A357 is the same material used in most aftermarket engine blocks along with many cast aerospace components.
  • 0.750” deck structure, thicker than all stock and most aftermarket castings
  • High efficiency water jacket – by increasing efficiency the overall water jacket has been reduced for overall strength without sacrificing cooling ability for all applications including endurance racing.
  • Raised runner design on both intake and exhaust – Raised runner design allows for more efficient cylinder filling, better high-rpm operation without sacrificing low and mid-range performance. Greater flow characteristics, especially when combined with our shallow valve angles. Intake flange is extended to allow all standard manifolds to fit without modification.
  • Exhaust port exit is on center with valve – Substantially better flow characteristics. LS7 bolt pattern moved to accommodate all standard header designs using 2” or larger headers.
  • Proprietary valve cover design – Enlarged valve cover based loosely on a SB2 pattern allows for more rocker clearance when using solid rollers, more spring clearance for larger diameter/higher lift packages. Valve covers included with purchase of heads. See valve cover section below for additional information. Valve covers are doweled and o-ringed for superior sealing and serviceability.
  • ¼” NPT water crossover ports – better cooling capacity and more flexible installation/plumbing options.


  • 15° inline valve angle – designed for True Street/Ultra Street and multi-kit nitrous applications.
  • Port & Chamber volumes / flow numbers TBD.
  • Standard version designed to work with GM LS7 rockers and equivalent. Doweled rocker stands included with head purchase.
  • Solid, stainless 2.200” Intake / 1.650” Exhaust valves standard – interlocking valve seats (like those found in racing heads) standard.
  • Accommodates up to 3/8” straight pushrods. See Rocker section for information on solid roller applications.
  • 4.125” minimum bore size (can be run on slightly smaller bores with proper head gasket).
  • Includes FED Titanium 0.660” Lift Spring Kit.
  • 294cc equivalent.

Valve Covers:

  • 319 aluminum alloy cast valve covers – same alloy used in most aftermarket and stock cylinder head castings.
  • Baffled vent section – Compatible with stock PCV/emissions components.
  • -16AN ORB Oil Fill cap included.
  • Available with built in coil mounts or without coil mounts.
  • Available in two powder coated finishes. Fully machined versions available upon request.

Solid Roller Options:

  • All F-Series Solid Roller cylinder heads available with shaft-mount, roller tip rockers.
  • Available for on-center and 0.180” offset lifters.
  • Solid roller heads will accommodate up to a ½” pushrod.
  • F-Series shaft-mount rockers will be available as standard catalog item.

F715 Components

New FED F7X A357 Cylinder Head CastingsCHF7XA357SI
FED PRIME Grade - Black Nitride Coated Stainless Steel Intake Valves 2.200 / 5.750"IVSS2200X5750FED
FED PRIME Grade - Black Nitride Coated Stainless Steel Exhaust Valves 1.650 / 5.750"EVSS1650X5750FED
Manley Polished Nextek HP Dual Spring 1.295" 155# @ 1.800/405# @1.150/.660 lift (Hydraulic) Standard KitSPR221436MLY
FED Titanium RetainersSPRFRT1001FED
FED Steel Valve Spring Locators - .565 - 16pcsSPRVSL565FED
GM Valve LocksSPR355005QC
Viton High Heat SealsSPRVS441USS
US Seal Hardened Spring ShimsSPRSHIMUSS
FED Valve Covers with Coil Mounts (set of 2) - Wrinkle BlackVCFCMWBFED
FED Billet Rocker Stands For Stock LS7 RockersRSF710FED
CHE F Series Intake Valve SeatsISTLS2350CHE
CHE F Series Exhaust Valve SeatsESTLS1700CHE
CHE F Series Intake Valve GuidesIVGIN2700CHE
CHE F Series Exhaust Valve GuidesEVGEX2700CHE
FED PRIME Grade - Black Nitride Coated Stainless Steel Intake Valve 2.200 / 5.950 (Solid Roller)IVSS2200X5950FED
FED PRIME Grade - Black Nitride Coated Stainless Steel Exhaust Valve 1.650 / 5.950 (Solid Roller)EVSS1650X5950FED
FED Inconel Exhaust Valve 1.650 / 5.750 (Hydraulic Roller)EVI1650X5750FED
FED Inconel Exhaust Valve 1.650 / 5.950 (Solid Roller)EVI1650X5950FED
PAC Racing Springs RPM LS Series Valve Spring - 1.204 OD / 0.680 ID / .700liftSPR1207XPAC
FED Valve Covers with Coil Mounts (set of 2) - High Gloss GreenVCFCMHGFED
FED Valve Covers (set of 2) - High Gloss Green NO COIL MOUNTSVCFHGFED
FED Valve Covers (set of 2) - Wrinkle Black NO COIL MOUNTSVCFWBFED
PAC Racing Springs 1200 Series Dual Valve Spring - 1.625 OD / 0.851 ID / .850 (Solid Roller)SPR1224PAC
PAC Racing 400 Series Valve Spring Retainers - Titanium (Solid Roller)SPRR404PAC
PAC Racing Valve Spring Locators - .575 Guide (Solid Roller)SPRS101PAC
Manley 10° Steel Valve Locks (16/pkg) (Solid Roller)SPR1315316MLY

General Recommendations for Frankenstein Cylinder Heads

  • High Volume/Pressure Oil Pumps – We recommend restricting the oil to the top end of the engine when using high volume/high pressure oil pumps. This will help prevent the valve seal from being submerged in oil and will help prevent smoking.
  • Pushrods – We recommend a clearance of at least .050 clearance between the pushrod and the wall. Do not clearance the pushrod holes any further, as this can cause damage and will void any warranty. Every lifter brand and style use a different pushrod length and customers are responsible for understanding how to verify the length needed for their application. We recommend a pushrod with a wall thickness of .120. Make sure to accurately check pushrod length and wall clearance. Products have a minimum port thickness in order to pass our QC.
  • Surfacing – Flat or angle milling will affect flow numbers and might require a thicker intake gasket.
  • Boosted/Nitrous Applications – Power adder applications causes increased stress and longevity issues for the valvetrain. We highly suggest the use of Inconel exhaust valves in any power adder combos. We also recommend the use of our upgraded valve spring kits to help properly control the valve train for these stressful conditions.
  • All MARINE Applications – We strongly recommend Inconel exhaust valves & also offer a hard-anodized coating to slow the effects of corrosion. Please see note on guide clearance below.
  • Valve Guide Clearance – FED cylinder heads come with proper guide clearance (.0012″-.0016″) for most applications. Boosted/Nitrous or marine applications might require additional clearance and it is the customer’s responsibility to verify proper clearance in these applications.
  • Valve Springs – Forced induction, nitrous oxide and cams with aggressive ramp rates may require additional spring pressure. We offer upgraded valve springs for these types of applications. FED also recommends the use of billet 8620 cam cores and short travel Johnson Hydraulic Roller lifters which tolerate higher spring loads.
  • Titanium Valves – These valves are coated with CRN and cannot be reground. This coating helps with rigidity and heat protection. If the valves are reground it will remove this protective coating and compromise the integrity of the valve thus increasing the chance for a valve failure. These valves also require a hardened lash cap to be installed on the tip of the valve. These valves are made from Ti-17 and are the best quality available in the industry.
  • Stainless/Inconel Valves – The F-Series steel valves are all coated with Black Nitride coating. Nitriding vastly increases the hardness of the metal that is treated without changing the material dimensionally like the buildup of a hard coat. This coating not only increases the strength of the valve but increases the longevity of the valve. This is not a spray on coating. This is a surface hardening process and is used a lot in aerospace and military components. We strive to only use the best!
  • Piston to Valve – FED will not be responsible for damage caused if the customer builds an engine and fails to verify he/she has enough piston to valve clearance (depth and radial clearance both checked). We recommend a minimum depth of .080″ on the intake valve and .100″ on the exhaust with a radial clearance of .030″ minimum around the perimeter of each valve. Checking depth is not enough, the position of the valve pocket must also be addressed. It is the customers responsibility to verify proper piston to valve clearance.
  • CNC Porting – Occasionally a 100% CNC ported head might have a very small area left “as cast”. This does not adversely affect product performance.
  • Valve Spring Installed Heights – FED valve spring installed height spec is +/- .015 which is the smallest shim available for adjustment. This small difference will have no issues and should be of no concern.
  • Stock GM Rocker Arms – GM Rocker Arms are not designed/engineered to endure aggressive aftermarket cams or higher spring pressures/rates. At minimum FED recommends using CHE Bushing Trunion Kits. Other available options include: Jesel aluminum and steel shaft mount rockers and Crower steel shaft mount rockers. Failure to use adequate parts will cause accelerated guide wear over an extended period of time.
  • Jesel/Crower Shaft Mount Rockers – These rockers must be used for any solid roller application or a high rpm, high cylinder pressure application.
  • O-Rings – FED uses O-rings to seal the intake, exhaust and valve cover flanges. These O-rings will wear out over time depending on how many times the customer removes the valve covers, headers, and intake manifold. Customers are responsible for checking them periodically during removal and installation of aforementioned parts to ensure product integrity.
  • Cylinder and Valve Cover Heights – The F-series heads are ½” taller from the deck surface to the top of the valve cover rail compared to stock castings. This may or may not cause clearance issues in some engine bays. The valve covers that must be used on these castings are also taller than stock by ½” and could potentially cause clearance issues as well in some engine bays. Corvette (Y-Body) front accessories alternator may need to some clearance put in. Customers are responsible for verifying clearance before purchase. Failure to verify clearance will not be a warranted reason for return of the product.
  • Head Stud Sizes – F-series heads come standard with clearance for 7/16” studs or smaller for the center 10 bolts and the outer tabs and the deck studs are machined for 8mm standard. Special order of ½” and 3/8” stud machining is available, however lead time will increase by 2 weeks.
  • Headers – All F-series heads will require LS7 header flanges. These flanges can be used for any make and model vehicle as long as you specify the LS7 flange. These headers must have a ROUND flange shape and ROUND header tubing coming off the exhaust ports. Non LS7 header flange use will result in partially covered exhaust port and could cause loss of power. Example: If you call Kooks headers and request a set of headers for a 2001 Trans AM, be sure to request the use of a LS7 flange.
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