# Proform 66509 | 66509 Harmonic Balancer; SB Chevy 350

### PROFORM 66509 APPLICATION SPECS:

### Attributes

-   Applications: Chevy Small Block 350 Engines 1955 to 1986
-   Category: Harmonic Balancer
-   Color: Natural Finish
-   Diameter: 6 3/4-in.
-   Finish: Natural
-   Internally/Externally Balanced: Internal
-   Material: Nodular Iron
-   RPM Limit: 6000 RPM
-   Thickness: 1 5/8 inch

### Product Description

100% New OEM Replacement Unit,Engine Harmonic Balancer,Includes Degree Markings,Fits Small Block Chevy 350 Internally Balanced Engines with a 6-3/4 Inch Balancer,Made From Nodular Iron and Features a Natural Finish,Non-SFI Approved

### FAQ

**What part number is this?** The listed part number is 66509.

**Is this product designed for direct replacement?** Confirm the original part specifications and intended application before ordering.

**Should I confirm compatibility before ordering?** Yes. Compare the original part and specifications before ordering.

### Common Searches

-   Proform 66509
-   66509 specifications
-   Proform Harmonic Balancer; SB Chevy 350

## Details

- **Price:** 251.88 CAD
- **Vendor:** Proform
- **Type:** Harmonic Balancer
- **Tags:** 66509, Harmonic Balancer, Proform

## Variants

| Variant | Price | Available |
|---------|-------|-----------|
| Default Title | 251.88 CAD | In stock |

## Images

- Proform 66509 | 66509 Harmonic Balancer; SB Chevy 350

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> Source: [Standard Auto Part](https://www.standardautopart.com/products/66509-vp-proform-518)
> Updated: 2026-10-20