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OPR Top End Engine Kit (87-93 5.0L)

Item 99941
AmericanMuscle no longer carries the OPR Top End Engine Kit (87-93 5.0L). Please check out 2015-2021 Mustang Crate Engines and Blocks for an updated selection.
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    Product Information

    Features, Description, Q&A, Specs & Installation


    • Bolt on More Horsepower
    • Complete Top End Kit
    • Improves Air Flow Over Original GT-40 Heads
    • Lightweight Aluminum Construction
    • Includes GT40X Heads, XE264HR Stage I Camshaft and Typhoon Intake Manifold
    • Fits 1987-1993 5.0L Mustangs


    More Power. Increase the horsepower and torque output of your push rod 5.0L engine with an OPR Top End Engine Kit from AmericanMuscle that includes Ford Racing Turbo-Swirl GT40X Aluminum Heads. This Top End Engine Kit will greatly improve airflow over the original stock design allowing you to bolt-on over 65 more rear wheel horsepower.

    Kit Includes.
    This Top End Engine Kit includes Ford Racing Turbo-Swirl GT40X Aluminum Heads, Comp Cams Xtreme Energy XE264HR Stage I Camshaft, Typhoon Intake Manifold, Aluminum Valve Covers, Magnum Double Roller Timing Chain Set, ARP High Performance Series Head Bolt Kit, and a Ford Racing Engine Gasket Kit.

    GT40X Aluminum Heads.
    Made from high quality 356-T6 aluminum castings, these Ford Racing GT-40X heads have an intake port volume of 178cc allowing for an intake flow of approximately 240 cfm at .550" lift (at 28" of H20) and an exhaust port volume of 62cc allowing for an exhaust flow of approximately 170 cfm at .500" lift (at 28" of H20). Machined for 1.94" Intake and 1.54" exhaust valve diameters.

    Xtreme Energy Stage I Camshaft.
    This Comp Cams Xtreme Energy Hydraulic roller lifter cam is a good replacement upgrade for the High Output (HO) 5.0 that was featured in the later Foxbody Mustangs for mild street performance gains. Perfect for bolt on modifications to make good overall power with a smooth idle without sacrificing daily drive-ability.
    Typhoon Intake Manifold. Completed in a natural satin finish this aluminum Professional Products Typhoon Intake Manifold will allow your Pony to breath much easier with no loss of low end torque. A 70mm Throttle Body is recommended for optimum performance of your 5.0 Mustang.

    This OPR Top End Engine Kit is designed for use on the 1987 to 1993 Mustangs equipped with the iconic 5.0L V8 engine, including the LX 5.0, GT and SVT Cobra models.


    CA Residents: WARNING: Cancer and Reproductive Harm -

    Installation & What's in the Box

    Installation Info

    What's in the Box

    • (2) Ford Racing Turbo-Swirl GT40X Aluminum Head
    • (1) Comp Cams Xtreme Energy XE264HR Stage I Camshaft
    • (1) Professional Products Satin Typhoon Intake Manifold
    • (1) Upper to lower intake gasket
    • (1) Upper plenum to intake gasket
    • (2) Canton Aluminum Valve Covers
    • (1) Filler Cap
    • (1) Comp Cams Crank Sprocket
    • (1) Comp Cams Camshaft Gear
    • (1) Comp Cams Timing Chain
    • (20) ARP Bolts
    • (20) ARP Washers
    • Ford Racing Complete Engine Gasket Kit

    Questions & Answers

    10 More Questions

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