Small Block Chevy 350 Build Pt. 12 | Checking pushrod length and installing pushrods
This video covers checking pushrod length and installing pushrods on a Small Block Chevy 350 as part of a rebuild. The process shows verifying pushrod length/rocker geometry with a checking method, lubing components, installing the chosen pushrods, installing rockers and torquing/setting preload or lash and then cycling the engine to verify operation.
Build Sequence
1. Prepare engine and access valvetrain
Remove valve covers (if not already removed), ensure the engine is at a safe work position, and rotate the engine to a convenient cylinder TDC or base circle depending on the checking method. Clean exposed areas to prevent contamination.
2. Seat lifters and verify lifter condition
Ensure lifters are properly positioned/installed and that the lifter tips are clean and free of damage. If lifters are new, prime/lube them per manufacturer instruction or ensure they are charged (for hydraulic).
3. Install adjustable pushrod checker
Install the adjustable pushrod/checker tool (or an adjustable length pushrod) into the lifter bores and place the rocker or rocker pad on the checking tool. This simulates the pushrod and lets you evaluate rocker geometry and contact area.
4. Verify pushrod length and rocker geometry
With the checker in place, rotate the rocker/rotate the engine as needed and examine where the rocker contacts the valve tip and rocker's roller/pad. Adjust the checker until you achieve correct center contact on the rocker pad/roller and appropriate lifter preload or rocker pad position. Record the required length.
5. Select and prepare final pushrods
Choose pushrods closest to the measured length. Inspect pushrods for straightness and damage, and apply a liberal coat of assembly lube to both ends of each pushrod.
6. Install pushrods and guideplates
Place each pushrod into its lifter cup and index it through any guideplates or clips. Ensure pushrods are seated fully in lifter bores and properly located in rocker arm cups.
7. Install rockers and torque to spec
Install rocker arms or rocker assemblies and torque the nuts/studs to manufacturer specifications. For hydraulic lifters follow the procedure for preload; for solid lifters set valve lash using a feeler gauge to spec.
8. Cycle engine and recheck
Manually rotate the engine through several full cycles (or follow the break-in/initial start procedure), then recheck rocker geometry, pushrod seating and lash/preload. Retorque or readjust where necessary after the initial run-in.
Frequently Asked Questions
How do I know when the pushrod length is correct?
The correct length results in proper rocker contact centered on the rocker pad or roller and the correct lifter preload or valve lash per the lifter/rocker manufacturer's procedure. Use an adjustable pushrod/checker to simulate the final rod and verify geometry before ordering or installing final pushrods.
VIEW FULL ARTICLE →Do I need a special tool to check pushrod length?
While not strictly required, an adjustable pushrod checking tool or pushrod checker makes verifying length and rocker geometry far easier and more accurate than trial-and-error with fixed-length rods.
VIEW FULL ARTICLE →Can I reuse old pushrods?
You can reuse pushrods only if they are straight, undamaged, and the length matches the required specification. Inspect for bends, wear at ends, or scoring; if in doubt, replace them.
VIEW FULL ARTICLE →How tight should rocker nuts be?
Torque rocker nuts to the manufacturer's specified torque value for your rocker assembly and stud type. For hydraulic lifters follow the recommended preload procedure rather than a single torque-only value. The video demonstrates torquing to spec rather than quoting a generic number.
VIEW FULL ARTICLE →Related Builds
Small Block Chevy 350 Build Pt. 6 | This Is How It's Actually Supposed To Be Done
Small Block Chevy 350 Build Pt.3 | Filing rings and checking main clearances
Small Block Chevy 350 Build Pt.5 | Continued frustrations with rod clearances
Small Block Chevy 350 Build Pt. 11 | Installing the intake manifold and figuring out sbc nuisances
Small Block Chevy 350 Build Pt. 7 | Checking Crank Clearance and installing the rods.
Small Block Chevy 350 Build Pt. 8 | Installing Camshaft and timing componentsParts Used (3)
Final set of pushrods chosen after checking length; use correct wall thickness/OD for guides and clearances.
Keeps pushrods indexed and prevents rotation; may be used if applicable to the setup.