Is plastigauge accurate enough for checking main clearances?
Documented on the Chevrolet Small Block 350 (sbc 350) build
Published March 28, 2026
Plastigauge is accurate enough for quick checks and verification, but it's not as precise as micrometer and bore gauge measurements.
Full Answer
Plastigauge is accurate enough for quick checks and verification, but it's not as precise as micrometer and bore gauge measurements. For final bearing clearance confirmation on performance builds, more precise measuring methods are recommended.
Documented In This Build
Related Knowledge
Why do you file piston rings instead of buying pre-gapped rings?How much end gap should I aim for on a SBC 350?How much material should I remove when filing a ring?What if my main clearances are out of spec?How important is degreeing the cam?What torque sequence and values should I use for SBC heads?How do I set lifter preload or hydraulic lash?What should I do to prepare the engine for first start and break-in?
Related Parts
Assembly lube
$15
Main bearing set
$60
Piston ring set
$120
Plastigauge (assorted)
$8
Related Tools
Torque wrench
Engine stand
Feeler gauges
Ring filer / hand file
Micrometer / inside micrometer
Plastigauge
Ring compressor
Related Videos
Small Block Chevy 350 Build Pt. 6 | This Is How It's Actually Supposed To Be Done
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 components
Small Block Chevy 350 Build Pt.1 | Lifting This Engine Without Breaking It