I’m trying to put together a kit using Doug’s helpful “Bolt Size and Tightening Information - 170, 198 & 225 Slant Six Engine,” published 1-29-20 and available on this site.

The McMaster-Carr catalog shows bolts available with and without a non-removable washer, like some of the OEM bolts.

Short of removing all the bolts from an unmolested engine, is there a guide to tell which bolts come with a washer and which do not?

Should I source the bolts from McMaster-Carr, or look elsewhere?

TIA

–Walt Jackson

The OE bolts will likely have an underhead flange headed in with the bolt head. That makes the assembly line job much easier as the line worker does not need to assemble a washer to each bolt.
The washer or enlarged flange spreads to clamp load and helps to prevent deformation and under head galling.
After market bolts will typically have a loose washer.
Look around on eBay or other aftermarket sellers. Someone likely has a slant six engine bolt set, probably stainless steel.
I would re use the existing head bolts as long as the threads look good.
For other critical fasteners like rod and flywheel bolts, ARP will have those. Just be sure to use the ARP bolt lube and torque specifications.

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