How do I know if my rod clearances are too tight or too loose?
Documented on the Chevrolet Small Block 350 (sbc 350) build
Published March 28, 2026
Measure crank journal and rod bore diameters with a micrometer/dial bore gauge and use Plastigage during mock assembly to read bearing oil clearance; compare readings to Small Block Chevy 350 spec charts.
Full Answer
Measure crank journal and rod bore diameters with a micrometer/dial bore gauge and use Plastigage during mock assembly to read bearing oil clearance; compare readings to Small Block Chevy 350 spec charts. Tight clearances cause binding or heavy drag on rotation; loose clearances show excessive flattened Plastigage and may cause low oil pressure or knocking.
Documented In This Build
Related Knowledge
Can I file or grind my rods myself to correct interference?What causes repeated rod clearance problems on a SBC 350?When should I replace rod bolts?Is Plastigage accurate enough for final clearance checks?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
$12
Connecting rod bearings (set)
$65
Main bearing set
$90
Plastigage (clearance measurement)
$9
Thrust washers
$25
Machine shop work (rod resizing/grinding/match-fit)
$180
Rod bolts (ARP or equivalent)
ARP (typical upgrade)$85
Related Tools
Torque wrench
Engine stand
Micrometer (0-1")
Dial bore gauge / dial indicator
Plastigage
Die grinder / sanding tool
Basic hand tools (sockets, ratchets, breakers)
Feeler gauge set
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.3 | Filing rings and checking main 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