rocker arm interchange

[Max B]

I've not been able to locate a definite answer to question.
I have a 65 289 code A with the steel rocker arms. I also have a 68 289 and 69(?) 302 unused crate engine.
I understand the later cast style rail rocker arms are trouble prone when worn to cause wear on valve stems, locks and keepers,
As I would like eventually to use 302 in my Sunbeam, wondering if old style rockers will "bolt on" in place of rails. I am also aware of need for push rod guides.
Thanks.

 

[hottigr]

Max, I don't think this is a direct answer to your question, but perhaps some of this info may be helpful. I have a '63 289 block with 302 connecting rods in my Tiger. I had the heads done 34 years ago and installed guide plates as well as chrome moly pushrods (I think they were Sig Erson). I still have steel rocker arms. Everything is still good 34 years later. Kirk.

 

[HolyCat]

I thought there is a difference in rocker arms depending on the SBF heads. As I remember (please double check before relying on this information) the early heads had a circular opening for the push rods to go through. In order to keep the push rods from moving side to side, the rocker arms had a box-like end to reduce the push rods' side-to-side motion. Later heads had a slit for the push rods (eliminating the ability of the push rods to move side-to-side) and plainer heads on the rocker arms were used, with less mass moving up and down. Also, in the back of my memory, I think there were guides which could be bolted on under rocker arm studs) and would limit the side-to-side motion on heads with the round hole for the push rods.

I don't know if this answers your question, though, as I do not know what type of heads you have.

 

[hottigr]

My heads are 289 '64 1/2 heads with the circular opening that eroded and allowed for the pushrod to change the geometry. I put the guide plates on, and it eliminated the problem. Also, screw in rocker studs.

 

[Austin Healer]

I thought there is a difference in rocker arms depending on the SBF heads. As I remember (please double check before relying on this information) the early heads had a circular opening for the push rods to go through. In order to keep the push rods from moving side to side, the rocker arms had a box-like end to reduce the push rods' side-to-side motion. Later heads had a slit for the push rods (eliminating the ability of the push rods to move side-to-side) and plainer heads on the rocker arms were used, with less mass moving up and down. Also, in the back of my memory, I think there were guides which could be bolted on under rocker arm studs) and would limit the side-to-side motion on heads with the round hole for the push rods.

I don't know if this answers your question, though, as I do not know what type of heads you have.

you are correct about the early vs. late rockers. they newer style is interchangeable w/o any other modification

 

[Erich]

Early Ford heads (up to about the middle of 66 model year) have a narrow oval slot. The slot controls side to side position of the pushrod.
Push rods must be hardened.
Push rod controls orientation of rocker.

Later heads have a much larger diameter round hole in the head.
This design uses the rails on the side of the rocker to guide the rocker on the tip of the valve stem.

Later still Ford switched to fulcrum rockers that get rid of the rail. The rocker pivot motion is a cylinder. All previous designs, the rocker pivot was a spherical ball.

 

[Max B]

Thanks all. it's my understanding those rails were an economics decision by Ford, but when didn't work, changed to fulcrum. My question was if the earlier 63-661/2 style rockers, which I have in good shape, could be swapped with rail for more reliability, realizing would need guides for push rods. I knew dimensions all seemed same, but didn't know.
I believe Sean remark was what I needed to know. Thanks. You folks are great.
Max