Complete Small Block Ford Windsor 289 302 351 175cc Alloy Cyl Heads

Complete Aeroflow 175cc Aluminium Cylinder Heads for Ford Windsor (289-351)

Unlock street‑and‑strip performance from your Ford Windsor with a complete pair of Aeroflow 175cc aluminium cylinder heads. Crafted from premium A356‑T6 aluminium, these heads are built for efficient flow, durability, and a budget‑friendly price point. Designed to shine from idle up through mid‑range RPM, they’re a practical upgrade for 289–351 small‑block builds seeking real torque and strong, reliable operation.

Why these heads stand out

• Premium material: A356‑T6 aluminium delivers light weight with robust durability.
• Consistent flow and sealing: 61cc combustion chamber, 175cc intake port volume, and 66cc exhaust port volume between the heads for balanced power across the range.
• Precise porting and combustion: 5‑angle competition valve job, diamond‑honed bronze valve guides, hand bowl blending, and professional assembly for improved flow and reliability.
• Accessibility and sealing: Angled spark plug location to enhance accessibility across various header configurations.
• Balanced valve train: Intake valve 2.02" and exhaust valve 1.60" with 11/32" valve stems and manganese bronze guides.
• Rocker/valve train hardware: 7/16" x 14 rocker stud threads for solid adjustability.
• stout valve springs: Larger‑than‑stock springs with 1.440" OD, 1.130" ID, installed height 1.800", installed pressure 125 psi, open pressure 300 psi at 500" of lift; capable of up to ~0.525" lift (max 0.600" @ 1.200").
• Full hardware package: Retainers (outside 1.400", inside 0.395"), two retainer steps (1.060" and 0.685"), locator (1.550" OD, 0.565" ID).
• Deck design for sealing: 0.625" deck thickness to promote proper quench and sealing characteristics.
• Cam compatibility: drilled for 1/2" head bolts; for 7/16" bolts, a head bolt bushing kit or step‑down bolts is recommended.

Technical specifications at a glance

• Applications: Small Block Ford Windsor 289–351
• Chamber size: 61cc
• Intake port volume: 175cc
• Intake port dimension: 2.00" x 1.18"
• Exhaust port volume: 66cc
• Exhaust port dimension: 1.32" x 1.27"
• Spark plug location: Angled
• Intake valve: 2.02" diameter
• Exhaust valve: 1.60" diameter
• Valve stems: 11/32"
• Valve guides: Manganese Bronze, O.D. 0.530" (base 0.570")
• Rocker stud thread: 7/16" x 14
• Valve angle: 20°
• Deck thickness: 0.625"
• Spring data: Installed height 1.800" • Installed pressure 125 psi • Open pressure 300 psi @ 500" lift
• Spring outer diameter: 1.440" • Inner diameter: 1.130"
• Free length: 2.200"
• Maximum lift: 0.600" @ 1.200" (capable up to ~0.525" lift)
• Valve spring retainers: Outside diameter 1.400" • Inside diameter 0.395"
• Retainer steps: Step 1 1.060" • Step 2 0.685"
• Spring locator: Outside diameter 1.550" • Inside diameter 0.565"

Installation and build considerations

• These heads are drilled for 1/2" head bolts. If you’re using 7/16" bolts, you’ll want a head bolt bushing kit or step‑down bolts to ensure proper fit and seal.
• Check installed spring seat pressure and open pressure before installation to ensure correct spring pressure for your specific application.
• Designed to pair with flat tappet cams and tuned for reliable performance across idle to mid‑range RPM, up to the 6500 rpm window in typical street builds.

What this means for your build

This pair of 175cc Aeroflow heads is engineered to deliver solid street performance with competitive flow across the idle‑to‑6500 rpm window. Expect improved low‑ to mid‑range torque, refined response, and dependable sealing characteristics thanks to a precise 61cc final chamber, optimized port geometry, and meticulous assembly. The angled spark plugs, enhanced valve train hardware, and robust valve springs give you the flexibility to tune for daily driving, weekend drag sessions, or a balanced street/strip setup without breaking the bank.