XXTREME 245 LS1/LS2 Cathedral 3.898 Small Bore (SOLD IN PAIRS)


The 245 cathedral head is the best of both worlds with the 11-degree valve angle and cathedral port shape. No cathedral head can come close. Independent dyno tests have shown an LS1 to produce over 490 horsepower to the wheel through a 4l60 transmission with factory manifold and cam on pump gas.

Requires 3.898″ bore minimum and LS3 intake rocker.

Call for to 2.125 upgrade

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  • Pro designed ports & chambers
  • 245cc as-cast port designed and tested in the USA
  • Ultra-smooth 356-T6 Aluminum Casting
  • 5 angle valve job
  • 63CC or 59CC Chamber size or additional options available
  • 11 Degree Valve Angle
  • Diamond honed guides
  • Built-in raised valve cover rail
  • Monster .750 deck thickness
  • Billet LS3 OEM Rocker Stand
  • For use with standard or 6 bolt pattern
  • Large spring pockets
  • Utilizes 2.08 intake valve and 1.60 exhaust valve (Larger sizes available upon request)
  • Multiple spring options
  • Assemblies include: 21-4N stainless 1pc swirl polished back cut valves
  • Machined and Assembled in the USA
  • Outperforms other comparable heads in the industry