Finding replacement 258 rocker arm

I've got a busted rocker arm on my '73 258. I'm having some trouble finding a replacement. All the ones I can find on the web are for about a 75 and up. They look very similar. Also, there are ones for a 304 my model that look very similar. Anyone had any expericne finding these??

 

AFAIK there are two designs - bridges and shafts.

Jeep changed from bridges to shafts to bridges in the '73-74 time frame, so the online sources are likely playing it safe and only claiming coverage of those years they can be certain of. If you have bridges, I would guess they are the same as a '72 model. The '71-72 also has bridges, which could have lapped over into 1973. Pretty sure all '74s used shafts.

My parts book only covers '74 on, but someone with an older parts book could give you a Jeep PN which you could compare to what's available. The Jeep parts book should break this down precisely by year model and SN.

This situation would be helped if you were friendly with a local parts store. They could order the parts for you, and send them back if they aren't right. Doesn't cost them anything but their time, and a good store should be happy to do it for a regular customer.

 

Found one on the net but not on ebay they are specialty vendor for jeep cj parts which is cheaper than the one offered.

 

I just replaced all of mine last Thanksgiving, arms, pivots and bridges. My '73 used the same as '74. Advance has the kits for $13.99 right now.

 

Just for information purposes...
My August 16 1974 built 258 uses bridges.

 

The Jeep parts book shows two cylinder heads for 1974, identified by shafts or bridges. I don't know what the story is about this, but both types of heads were used in this time frame. Federal-Mogul shows bridges for 1974, but nothing for 1973 or 1972.

I'd also be careful to get the right length pushrods ... these changed too (and again in 1977, indicating a change in rocker geometry).

Maybe {If you have a problem getting parts for an earlier head, I'd suggest you just get another head. Heads for 232s and 258s are dirt cheap on the used market, and the parts for the later heads are readily available.}

There may be oil passage differences with the change from shafts to rockers. I'll need to check.

Ok, more consulting the books. There's only one block for a '74 232/258, so either head design should work. This is a little strange, since Jeep kept both styles of complete engines in the parts book ... not sure why the bridged rocker engine would not be the correct service part for the shaft rocker engine. Hmm.

I then found you should be ok to go from the cast (shaft) rockers to the bridged rockers, but maybe not vice-versa. The oiling for the cast rockers comes from the #3 cam bearing and up through the block and head to a rocker shaft pedestal. It then travels down the middle of the shaft to each cast rocker, where it lubes the rocker pivot and drips out on the top of the pushrod. The oil drains down the outside of the pushrod and back to the crankcase.

The bridged rockers use hollow pushrods to deliver oil to the rocker pivots. The lifter pumps the oil into the pushrod.

So switching to the bridged rocker head should be ok, since the passage from the #3 cam bearing will be blocked by the new head. I'd guess that passage is present in all blocks, but there's no way to tell from here. Just be sure to use the lifters and pushrods that go with that head.

I found several pages on this and related topics if anyone is interested in more detail.