Tom Henry Racing's Engine Shop.

 In late-October, 2005, Tom Henry Racing announced the latest of its "Phase II" performance-enhanced, engine packages, a 403-cubic inch, "Stroker" version of the LS2 used in '05/'06 Corvettes and SSRs.

Phase II Stroker features:

  • Callies, 4 in. stroke, forged steel crankshaft

  • Manley 4340 forged steel, I-Beam connecting rods

  • JE forged aluminum, 11.0:1 pistons

  • THR/Crane roller hydraulic camshaft, roller lifters and pushrods.

  • Crane "Quick Lift", 1.7:1, aluminum, roller rocker arms.

  • Crane dual valve springs and titanium retainers GM Performance Parts, CNC-Ported and milled LS6 heads w. 65cc chambers, hollow-stem valves

  • THR stainless steel, long-tube headers

  • High-flow mass airflow sensor

  • F.A.S.T. 90mm throttle Body, fuel rails and 42.5 lb/hr. injectors

  • THR/Z-Industries custom-calibrated computer upgrade

*Output:

Approximately 550hp SAE Net (flywheel) for C6 Corvette

Phase II Stroker prices start at $16,900.00* and will vary depending on how the donor engine is equipped prior to upgrading.

The first Phase II Stroker went together at the THR Engine Shop in mid-October. The gold rocker arms are the Crane's Quick-Lift 1.7:1 units which use a different pushrod seat location to enhance their geometry such that duration at low and medium valve lifts is significantly increased.


A couple of weeks later the first THR Phase II Stroker, ready to install in a customer's 2005 Corvette.

The Phase II Stroker, joins THR's Phase II Engine Packages for 350 cubic inch engines in '98-'02 Camaros, '97-'04 Corvettes, 05/06 Cadillac CTS-v's and 366-cuin. LS2 engines in 05/06 Corvettes. The THR Phase II 350 and 366 produces between 475 and 500hp depending on application.

Phase II features:

  • THR/Crane roller hydraulic camshaft, roller lifters and pushrods.

  • Crane roller hydraulic lifters and pushrods

  • Crane "Quick Lift", 1.7:1, aluminum, roller rocker arms.

  • Crane dual valve springs and titanium retainers

  • GM Performance Parts, CNC-Ported and milled LS6 heads w. 65cc chambers, 10.5:1 compression and lightweight, hollow-stem valves

  • THR stainless steel, long-tube headers

  • High-flow mass airflow sensor

  • LS6 intake manifold (early LS1 engines, only)

  • THR/Z-Industries custom-calibrated computer upgrade

*Output:

  • Approximately 475hp SAE net (flywheel) 390hp (rear wheels) for 98-02 Camaro

  • Approximately 500hp SAE net (flywheel) 425hp for C5/6 Corvette

Phase II prices start at $9900.00*, however, the price will vary depending on how the donor engine is equipped prior to upgrading.

Watch this space for more information on the Tom Henry Racing Phase II Engine Packages.

The first Phase II 350 was built for Tom Henry's personal SS Camaro Convertible. Since then, a number of other Phase II's have been installed in various THR customer cars.

Click here for a  road test article about the Phase II-powered, 2002 Tom Henry SS Camaro Convertible.

*Specifications and prices subject to change without notice.