RHS Products

Racing Head Service, a company founded by racers, started out as a manufacturer of racing cylinder heads and became a premiere name in cylinder head performance.

The company is a member of the COMP Performance Group.

Known for their winning performance cylinder heads and blocks with their patented Clean Cast Technology, they have developed some of the highest flowing, best performing cylinder heads and intake manifolds in the performance aftermarket and the most advanced engine block ever built  for GM LS engines.

Their product line includes:

  • LS Race engine blocks
  • Cylinder heads
  • Parts kits(cylinder head assembly, bolts & studs)
  • Valve train(guide plates, polylocks, pushrods, rocker arms, rocker studs, stud girdles  & valves)
  • Gaskets (intake, exhaust & valve cover)
  • Spark plugs (Champion & Zex)
  • Intake manifolds (for GM LS & SBC)
  • Big Mouth Throttle bodies (for GM LS)
  • Tools (for cylinder head, engine block & pushrod, abrasives and simulation software)


Designed from heavy-duty A357-T6 aluminum material.

  • Siamese cast bore walls (4.100” – 4.165”) with press-in spun cast iron liners
  • Available in standard (9.240” or 9.250”) & tall (9.750” or 9.760”) deck heights with beefy deck thickness (.500” standard/.750” tall deck); standard (5.87”) & tall (6.38”) deck cylinder sleeves available
  • Extra long liners for standard (5.87”) & tall (6.38”) decks
  • Long arm friendly” design – Accommodations for up to 4.6” stroke with standard rod pin diameters (2.100”) & oversized 60mm camshaft
  • Designed for clearance – side oil galley moved outboard & engineered rod clearance come standard
  • Raised cam centerline (.388”/9.86mm) to allow larger stroke; 2 extra links in the timing chain – Timing sets available from COMP Cams®
  • Bay-to-bay breathing improved with increased side window area versus LSX & LS7

LS Aluminum Block Finished:
P/N 54900  (Tall (9.750″) Deck, 4.165″ Bore)              P/N 54901 (Tall (9.750″) Deck, 4.125″ Bore)
P/N 54902  (Standard (9.240″) Deck, 4.165″ Bore)      P/N 54903  (Standard (9.240″) Deck, 4.125″ Bore)

LS Aluminum Block Bored, Ready to Hone:
P/N  54900U  (Tall (9.750″) Deck, 4.160″ Bore)            P/N : 54901U  Tall (9.750″) Deck, 4.120″ Bore)
P/N 54902U  (Standard (9.240″) Deck, 4.160″ Bore)     P/N 54903U  (Standard (9.240″) Deck, 4.120″ Bore)

LS Aluminum Race Block Unfinished:
P/N 54904  (Tall (9.760″) Deck, 4.100″ Bore)
P/N 54905  (Standard (9.250″) Deck, 4.100″ Bore)


They offer a wide variety of cylinder heads from stock replacement to hardcore racing (bare or assembled heads), all to maximize the performance of each unique engine application.

Pro Torker Series

  • Designed  for stock replacement and mild street performance applications.
  • Cast Iron core material for maximum consistency and durability
  • Clean Cast Technology delivers enhanced airflow & performance

Pro Action Series

  • Designed for hardcore street, race and powerboard engine applications
  • Available in cast iron and aluminum with a wide variety of runner and chamber sizes
  • Enhanced features and superior quality out-perform the competition right out of the box

Pro Elite Series

  • Designed for extreme performance and race application – second to none
  • CNC-ported cylinder head designed for absolute maximum performance
  • Innovative cast iron and aluminum designs with race-inspired features
  • Deliver maximum airflow for remarkable performance  gains


RHS also offers various cylinder heads assembly kits, head bolt kits and head stud kits because  it comes to street performance and/or competitive racing, the horsepower capability of cylinder heads can be limited if not used with the ideal parts.

Cylinder head studs and components can mean the difference between high performance durability and stress-related component failures. These exclusive RHS® parts kits give you the ideal combination of components for your cylinder head assembly and are proven to offer superior performance to your specific engine application.


Your cylinder heads are only as good as the  valve train that works with them.

  • Guide Plates
  • Polylocks (Hi Tech, Magnum, Stud Girdle Adjusting Nuts)
  • Pushrods (Magnum & Hi-Tech)
  • Rocker Arms (Ultra Pro Magnum Stel and Ultra-Gold Aluminum)
  • Shaft Mount Aluminum Rocker Systems
  •  Rocker Arm Studs
  • Stud Girdles (Ultra Gold)
  • Sportsman Stainless Steel Valves


RHS offers high quality intake, exhaust and valve cover gaskets to suit many GM and Ford applications.

The intake and valve covers gaskets are made from a silicone-reinforced material for superb sealing characteristics and designed for reliable, leak-free performance – even when used in high-powered race engines.

The header gaskets feature  reinforced graphite construction for maximum heat resistance and protection against blowing out, ensuring that your exhaust system operates at peak efficiency.