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Small block Chevy rod bolt torque specs

Gen I, connecting rod bolts, stock hardware.

Standard 350 rod bolts are 3/8 inch: 45 ft-lbs with engine oil. Small journal engines use 11/32 inch bolts at 35 to 44 ft-lbs. Measure the bolt before choosing a number.

45ft-lbs
3/8" rod bolt, standard 350 with large journal rods
Thread prep: Engine oil on the threads and under the bolt head.
VersionTorqueNotes
3/8" bolt (350, large journal)45 ft-lbsJEGS and TorkSpec say 45; Summit says 40 to 45.
11/32" bolt (small journal)35–44 ft-lbsJEGS and TorkSpec say 35; Summit says 38 to 44.
7/16" bolt75 ft-lbsOne source (TorkSpec). Treat as unverified.
Watch outA standard 350 with large journal rods takes the 3/8" figure. Measure the bolt rather than assuming. Small journal engines look identical from the outside.
The widely copied 30–35 figureAn older, widely copied table lists connecting rods at 30–35 ft-lbs under a 3/8" heading. That number lines up with what JEGS and TorkSpec publish for the 11/32" bolt (35), so the heading appears to be mislabeled rather than the figure being wrong. Using it on 3/8" rods leaves them roughly a fifth to a third below the 45 ft-lb figure, which is well under-clamped. Sources do not fully agree on the small bolt either: Summit publishes 38 to 44 for 11/32", which is why that row is a range.

ARP rod bolts

Use ARP's number, not theseARP rod bolts run at a different clamp load. For example, ARP's kit for 305-327-350 large journal 3/8" rod bolts specifies 50 ft-lbs with ARP lube, against 45 for stock, and publishes a stretch figure of .0063". On rods, measuring stretch is more reliable than torque, and it is the method to use if the bolts have been used before.

If you are not using stock bolts with oil

HardwareWhat to do
Stock bolts, light engine oilThe condition the published figures assume. Use the figure as printed, with the thread prep noted above.
Stock bolts, dry threadsPublished figures assume lubricated threads. Dry, more of the effort goes into friction and the bolt ends up with less clamp load than the number implies. Prep the threads as specified, then use the standard figure.
Stock bolts, moly lubeMoly cuts friction, so the same wrench reading produces more bolt tension than the figure was written for. Using the standard number with moly on the threads over-stretches the fastener. Use the lubricant maker's correction, or switch to engine oil.
ARP bolts or studsDo not use the figures on this page. ARP fasteners run at a different clamp load and their torque is tied to their own assembly lube. Use the sheet in the box, or look up your part number.

Where these numbers come from

SourcePublished figure
JEGS3/8" with engine oil 45 ft-lbs; 11/32" with engine oil 35 ft-lbs
TorkSpec3/8" rod cap 45 ft-lbs; 11/32" 35 ft-lbs; 7/16" 75 ft-lbs
Summit RacingGen I table: 3/8" 40–45 ft-lbs, 11/32" 38–44 ft-lbs
Older widely copied table (outlier)connecting rod listed under a 3/8" heading at 30–35 ft-lbs

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