I'm preparing my 261 to replace the 235 that I removed from my 40 sedan.I am going to hone the cylinders and replace the rings and rod bearings. The bore is stock (standard), as are the rod journals. I'm wondering if I should reuse the rod nuts and/or use locks on the rod bolts. There were no locks on it from the factory. What say ye? thanks

Its never a bad idea to replace old components like that, but it will require that you to recondition the rods if replace them, so factor that into your budget as well.

Connecting rods bolts don't typically have locks fitted between the nut and the saddle. In the early L6 era Chevy used either a castle nut or a plain nut with a pal nut. Both prevent backing off. I prefer to use a jam nut instead of the pal nut.

The shop manuals from the day suggest that all of these components are reusable - except the pal nuts.

Many will have you believe that rod bolts are not reusable - in general. This is an over simplification. Some rod bolts are in fact designed for just one torque to yield. While other rod bolts carry an at rest length specification. These can be re-used over and again so long as they don't become permanently stretched .001 beyond spec.

I vote for reuse and avoid over torque (which is typically how over stretch occurs in the first place).

regards,
stock49

I agree with CNC-DUDE...any part like that that you can get new I'd get new.

Actually, I was just thinking about replacing the nuts , not the bolts. Although , one of the rods is now missing a bolt. I think the threads didn't look good when I took the piston & rod out a few years back so I took the bolt out. I have a couple of extra bolts & nuts, so I can replace it. I suppose it would be impossible to get an accurate torque reading if nylon-insert locking nuts were used? I've had other engines with castle nuts & cotter pins and one or two with the PAL nuts. I guess if these 235s and 261s didn't need them when new they don't need them now.

You need to spin the nuts on all the way down to the rod cap, if they do not spin down all the way easily, the nut or rod bolt should be replaced.

If you need to replace your rod bolts, normally you need to recondition/resize the rods.

Stock GM rod bolts are not much money I believe they are also not that strong either, so I would recondition the rods & use new rod bolts & nuts.


MBHD

I was never able to find new GM made rod bolts so I reused the old ones on several engines with no problems..
I believe ARP has rod bolts that will work. I remember guys using Ford 351C ARP bolts with a slight bit of grinding...
As mentioned, always resize rods when using different bolts..

Pioneer also makes replacement rod bolts. Its cheap insurance to replace them during a rebuild especially if you get the rods reconditioned.

Just changing the nuts won't provide much additional insurance as the bolt carries the bulk of the stresses the engine endures. The Stovebolt Performance Book says the Big Block Chevy bolts are interchangeable if you can't locate original style Stovebolt rod bolts.

I did some checking and the easy to find BBC bolts do work. but the heads need to beveled to match the stock 235 bolts.

Just like the Cleveland bolts i'm sure.