Advanced Induction Cylinder Head Development
100% CNC'd High Compression 218cc GM 5.3L LS1 Cylinder Head Package

GM's 5.3L LS1 head casting serves as the basis for this high compression / naturally aspirated oriented 3.900" bore specific offering.  With your 5.3's, lightweight Manley Race Master Stainless valves, and lots of available P2V this is a great option for 440-480rwhp 3.900" bore builds.  Our GM 5.3L CNC work will generate 11:1 compression on a stock 346cid LS1 while retaining the stock available P2V which allows the use of large duration cams without cutting piston reliefs!  Static compression ratios into the 12.X:1 range are possible.  Typical gains for this CNC work are in the 40-50rwhp SAE range over the as cast 241, and 346cid LS1's can manage 440-480rwhp SAE with bolt-ons and one of our daily drivable HR cam grinds.

Pricing is for work applied to a pair (2) of cylinder head castings and components YOU supply unless otherwise noted.  We are happy to build your heads with whichever spring kit, valve, etc. you would like.

Note: Over the years we have found these castings tend to require more time in regard to quality checks/corrections on our end. They also must be run with a larger aftermarket intake valve. Due to this, the cost is higher when using them as a base for work compared to the more common GM 243 etc.

Machining & Labor Operations:
  • 100% CNC Ported Intake, Exhaust, & Combustion Chambers
  • 100% CNC Professional Competition Quality Valvejob
  • Valves Cleaned & Precision Ground (whether using new aftermarket or re-using OE GM
  • PCD milled to ensure flatness, surface finish, & achieve desired chamber volume (50 - 60 cc)
  • Intake Flange, Exhaust Flange, and Valve Cover Rail PCD Milled to new surface finish specs
Machining & Labor + Manley Race Master 2.00 Intake Valves (using your stock Exh valves) Cost: $1395
Machining & Labor + Manley Race Master 2.00/1.55" Valves Cost: $1495

Labor and Component Options:

Bronze Guide Liners installed & honed to ideal clearances to refurbish worn out guides. - Cost: $125
Replace OEM guides with Full Bronze Guides & hone to ideal clearances - Cost: $250

PSI 1511 MaxLife Endurance Spring Kit w/ OEM Replacement Seals. - Cost: $280
Manley 23622 Titanium Retainers for OEM, PAC, PSI, etc. beehive springs - Cost: $195
BTR .660" Polished Dual Spring Kit w/ locators, viton seals, & Titanium Retainers - Cost: $300

Manley 221436 Nextek .660" shot peened & fully polished Dual Spring Kit:
    221436-16 Dual Springs
    23623-16 Titanium Retainers
    42334-16 Hardened Spring Locators
    13098-16 Precision Machined Locks
    Steel jacketed Viton seals for dual springs

    Cost: $525 bought w/ head work (This is a premium setup that is ~$700 shipped from Summit)

Dyno, Flow Bench, and Track Results: