Proline RPM Dual Valve Springs Kits Hydraulic ROLLER 11/32" valve, Fits 304 & 308 Cast Iron Heads *includes Locators*

Detroit Racing Products - Dual Valve Springs Kit - Proline Series -

High RPM Kit fits Holden 304 & 308 Cast Iron Cylinder heads.

*This kit includes a Hardened Spring Locator & Push On Teflon Seal*

Upgrade your Holden 308 with these compact, lightweight valve spring kits.*

Get maximum performance and RPM from your camshaft with these high-quality, USA-made valve springs.

The smaller outside diameter, LS-style design reduces reciprocating mass through lighter springs and compact retainers. Lower mass means less inertia and improved valvetrain stability at high RPM. Combined with high-frequency, multi-process heat treatment, these springs deliver premium durability and performance. The perfect Holden 308 Valve Spring package. 

The dual spring design provides critical safety redundancy—if one spring fails, the second prevents valve drop and catastrophic engine damage. Single beehive springs offer no backup protection.  

What's in the Kit?

• PAC Dual Springs - DRP-8417P-16  (Proline RPM series)
• Steel Retainers - 7 Deg *(can upgrade to tool steel)
• Locks - 7 Deg / 11/32" Valve square groove (Race Machined)
• Spring locators - suit .570" guide (common guide when cut down)
• Valve Stem seals: Teflon push on type - 0.530"  / 11/32" Valve

*Installation Note for Holden 304 & 308 Cast Iron Cylinder Heads: Holden 308 heads will need spring pads machined down to fit a 1.800" installed. The cast iron guide can be cut down to 2 different sizes, .630" & 0.570"

• Use Comp Cams cutter #4716CPG - 1.320" OD x 0.630" - Don't use the locator as the guide is now the locator
• Use Comp Cams cutter #4672  - 1.340" OD X 0.560" - Use with hardened spring locator.

Installed Height: 1.800"

Seat Load: 160lbs @ 1.800" /  181lbs @ 1.750"

Spring Rate:   417 lbs / inch

Max Lift: .670" @ 060" safety.

Made in USA.

BE ADVISED: IMAGE MAY DIFFER FROM ACTUAL PRODUCT.