LT1 Intake Manifolds

- USM HSR FOR LT1 STAGE I (Holley Stealth Ram C4 LT1 & optional Fuel Rail and Adapter Kit): UP TO 360 HP

- USM HSR FOR LT1 STAGE II (Holley Stealth Ram C4 LT1& optional Fuel Rail and Adapter Kit): UP TO 425 HP

- USM HSR FOR LT1 STAGE III (Holley Stealth Ram C4 LT1 & optional Fuel Rail and Adapter Kit) : UP TO 500 HP

- USM DEFIANT LT- STAGE IV INTAKE (Holley Stealth Ram C4 LT1 & opt. Fuel Rail and Adapter Kit) : UP TO 575 HP

All of our intakes are designed to make great power while maintaining a strong, flat torque curve. They are great for performance street and road racing applications.At USM we are building custom LT1 Intake Manifolds that meet your demands and exceed you expectations. We take pride in each and every Intake Manifold we build. All of our Intake Manifolds are built to order. As these are built to order, there are no refunds. We will work with you should there be any issues with our product. Our service does not end after the sale.

The 4 stages of porting are (all porting leaves lower third of runner for head matching):

STAGE I Our Stage I intake is designed for mostly stock LT1 Vette motors. Although some low end torque loss is expected, the usable Rpm range is significantly extended. Full length headers, exhaust upgrade and computer tune are strongly recommended. A camshaft upgrade is recommended as well.

STAGE II This intake is a good candidate for LT1 Vette motors with stock displacement and compression but with upgraded heads, cam and exhaust, or any combination.

STAGE III Designed for motors with higher compression or greater displacement running in the 500 HP range. A larger runner, more aggressive port blending and increased plenum are featured.

STAGE IV The largest plenum available in this line up at roughly 325 cid, this unit is built for torque and power for larger motors (383-427) running in the 550-600 HP range. Please call for recommendations.

LT1 Intake OPTIONS:

CUSTOM THROTTLE CABLE BRACKET

HOLLEY FUEL RAIL KIT (includes adj. Fuel pressure regulator and fuel line adapters)

COOLANT CROSSOVER ELIMINATION

THERMOSTAT HOUSING BLOCKOFF
70 rwhp over SuperRam!!!

Dyno results showing a comparison between the same engine originally equipped with the SuperRam vs the USM HSR. (figures reflect rwhp)

Intake PKpwr PKtq TQplot

SR 335@5400 420@3800 340+ from 2k to 5.2k rpm

USM HSR 405@6100 405@4900 340+ from 2k to 6k rpm

"The engine feels like it is breathing well past 6000.... The bottom end feels just as strong 2200 2500 and it screams to 6000+." - Dave B., (90 Corvette)
WARRANTY: USM products are warranted to be free of defects in materials and craftsmanship when they leave our facility. Claims must be made within 10 days from shipment. Circumstances of customers application, installation, and use are beyond our control. As such we make no warranty against failure during use. Any alteration or improper use will void this warranty. Warranty is limited, at our discretion to replacement, repair or shop credit of the defective merchandise. Warranty does not cover any direct or indirect cost, such as labor or damages of any kind arising from the use of USM products. It is the buyers responsibility to insure proper installation of the products purchased from USM.

Please call or email us to order or infomation!