Advanced Induction Cylinder Head Development
Ai 212cc CNC'd TFS 21° LT1 Cylinder Head Package

Our 212cc CNC'd 21 Degree TFS heads are one of our premier cylinder heads, with a professional racing level finish, and attention to detail.  They're ideally suited for those looking for the high HP potential of our CNC'd 23° TFS heads, but with the ability to generate high compression ratios on as little as 350cid.  Furthermore, they're built with high-end full bronze guides, lightweight 8mm / 5/16" valves, and the highest quality spring setup available - PSI's with our custom lightweight tool-steel retainers.  With supporting modifications this head is capable of producing approximately 525-575 SAE corrected horsepower with a daily driveable HR or SR camshaft, and well in excess of 600hp with more aggressive valvetrain packages and appropriate supporting modifications.  Our standard PSI beehive & lightweight steel retainer easily controls aggressive HR and mild/moderate SR lobes.  Higher load spring options are available for hydraulic and solid roller.

Machining & Labor:
  • 100% CNC Ported Intake & Exhaust runners
  • 100% CNC Unshrouded & Contoured Chambers
  • 100% CNC Professional Competition Quality Valvejob
  • Bronze guides honed to ideal clearances per application
  • Additional CNC'd Pushrod Clearance (required for 3/8" pushrods or 1.6+ rockers!)
  • PCD milled to ensure flatness, surface finish, & achieve desired chamber volume (54 - 63 cc)
  • Professionally assembled for your specific intended use, camshaft, & valve train setup
Components:
  • TFS 21° LTx Porter Castings
  • PSI MaxLife Springs (.650" Max net lift)
  • Ai Lightweight Tool-Steel Retainers
  • Manley Precision Machined & Hardened Steel Locks
  • Ai Custom Machined & Hardened Chrome Moly Locators
  • Lightweight 8mm Ferrea Stainless Valves - 2.055" Int & 1.600" Exh
  • OEM Quality Steel Jacketed Viton Seals


  • Optional @ Lower Cost: BTR .660" Capable Dual Spring Kit w/ Titanium Retainers


Cost: $3995 w/ Ai Ultimate HR Spring Kit, or $3795 w/ BTR Dual Spring Kit


Labor and Component Options:
Hollow stemmed, or Inconel valves for extreme power adder - Cost: +$POR
Upgrade to Ai Custom Lightweight Titanium Retainers (for PSI spring option) - Cost: +$POR
PSI .700"+ solid roller dual springs w/ Xceldyne Ti-17 Retainers & locks - Cost: +$POR

Add an Ai Billet Core Custom grind camshaft + In-House QC for $595-695 (depending on cam core/gear required)
Add an Edelbrock AirGap LT1 Intake Manifold + 58mm TB with or without porting.
Complete matching Heads / Camshaft / Valvetrain / Gaskets / Manifold / TB setup.

 Recommended Usage: 350 cid - 396 cid short blocks, for a wide variety of applications from NA to power-adder.  A very versatile head that can be altered slightly for your specific application at no additional charge.