Engines and Components› Camshafts and Valvetrain

GSC

+1mm Intake Valve

$171.12

SKU: 2004-8

Special Order
Special Order
Ships in 4–6 weeks
Free Shipping over $200
$100 Minimum Order
30 Days Return
INSTALL DIFFICULTY
DIY PRO SHOP

Advanced — 4+ hours

Overview

The GSC Power Division 2004-8 is a set of eight intake valves designed for Mitsubishi 4G63T engines. These valves feature a 35mm head with a +1mm oversize, and are back-cut to reduce weight for higher RPM and boost pressure capabilities. The swirl-polished heads promote smoother airflow over the valve, while the micro-polished stems minimize oil retention and drag for smoother motion.
Show original supplier description
The GSC Power-Division Intake Valve is engineered to be the best performance and longest-lasting valve available for the aftermarket, specifically for the 4G63T engine. Utilizing advanced 3D design and simulation software, GSC has developed a stronger, higher-flowing valve head. These valves have undergone rigorous flow testing in specific applications to ensure maximum flow rate. The materials used minimize valve distortion at the face, leading to better sealing under extreme conditions and consistent performance over time, establishing a new industry standard for sport compact performance valves. Key features include swirl-polished heads for smoother airflow, a back cut to reduce valve weight for higher RPMs and boost pressure, and micro-polished stems for reduced drag and improved motion. The intake valves are made from modified 21-4n stainless steel, chosen for its high heat capacity and durability. Valve tips are either hardened or feature a stelite wafer tip for extended life, and tip heights are adjusted to minimize the need for valve tipping, maintaining proper valve train geometry and reducing installation time. The keeper groove is also adjusted to balance spring pressures, reducing the need for shims and maximizing the performance of GSC's spring and retainer kits. The valve specifications include a 6.6mm stem diameter, 109.60mm overall length, and a 35mm head diameter (which is +1mm over standard).

Product descriptions are provided by our supplier partners and may not always be perfectly accurate. Not sure this fits? or call (760) 282-4645 and we’ll verify before you order.

Fitment

Fitment Guaranteed

Don’t gamble
on fit.

Log your build in the MOTORMIA app and we’ll guarantee this part fits your exact setup — or your money back, return shipping covered.

Available on iOS & Android

Specifications

BrandGSC
Part Number2004-8
CategoryEngines and Components
5,000+ Trusted brands
1M+ Enthusiasts
5M+ Parts sold
(760) 282-4645 hello@motormia.co

Buy with Confidence

Returns & Fitment

Built for enthusiasts. Every order is backed by our 30 day return window on eligible items. Unused and uninstalled products may be returned with approved RMA and no restocking fees when received in new condition. Orders placed through the MOTORMIA app with a complete build qualify for our Fitment Guarantee — free return shipping if the part doesn’t fit your exact setup. The guarantee covers fit only; installation must follow manufacturer instructions, and we recommend a qualified shop for parts marked Difficulty 4–5.

View Full Return Policy

Shipping

Orders are processed in 1–3 business days. In stock parts ship promptly from our partner network. Special-order items either aren’t currently stocked or are built to your spec — expect 4–6 weeks. If a part goes on backorder while your order is in the queue, we’ll reach out and work through discounted alternatives together.

Free shipping over $200 in the continental US. Alaska, Hawaii, U.S. territories (Puerto Rico, U.S. Virgin Islands, Guam, American Samoa, and the Northern Mariana Islands), and international orders carry surcharges — most appear at checkout. Some exceptions (LTL freight, or suppliers who quote freight only after we place the order) won’t. In those cases we’ll reach out with the exact charge before your order moves forward.

View Full Shipping Policy