0 rocker arms BIG or small 0 ? differences?

[zman1969]

I just bought a set of 0 rockers for my 302 and a few of them have a different style 0 some large and some small - I was wondering what the difference was if any?

[69Z28]

From what I have read recently the big O were fefore 69 and the small O was 69 and after. As for material differences I don't believe there are any.

I just bought a set of 0 rockers for my 302 and a few of them have a different style 0 some large and some small - I was wondering what the difference was if any?

[zman1969]

anyone else have any more info?

[69Z28]

I found where I read it. If you have Jerry M's revised 4th edition Definitive book on page 26 there is a pic of both versions of the 'O'. It says research shows the 67 Z28 had the larger 'O' than the 68 and the 69.

[JohnZ]

Chevrolet used 240,000 stamped rocker arms EVERY DAY; it's highly unlikely that there was only one supplier or one set of precision progressive-die tooling.

[69Z28]

At least that explains why I have a few rockers with the 'O' horizontal, vertical, small and large. Wow. Can I assume they were mixed this way on a given engine?

Chevrolet used 240,000 stamped rocker arms EVERY DAY; it's highly unlikely that there was only one supplier or one set of precision progressive-die tooling.

[x77-69z28]

Yes

[68camaroz28]

Umm, let's see some O's.....

70 Z/28

72 LT1

11A 69Z small O sideways

Mixture of O's

\

[68camaroz28]

One More:
TRW rocker

[tmodel66]

Has anybody ever saw an O with a line thru it? I've got a set in a box in my shop. I replaced them with Crane's cause they are in a Crane box. I can't remember what they were for though.

[69Z28]

Exactly what I have too.

Umm, let's see some O's.....

70 Z/28

72 LT1

11A 69Z small O sideways

Mixture of O's

\

[canadair]

the rockers with the triangle are they also high performance rocker arms ?

[69Z28]

Honestly,don't really know anything about them. Mostly installed on low performance engines. Just a guess though but probably didn't get a process that the 'O' rockers received.

[jdv69z]

Here's my original set.

[69Z28]

Just out of curiosity, I have heard it's best to keep the same pivot ball to the same rocker. Are there any exceptions or is it a must to get new pivots? Mine are all mixed up in a box, all look fine with no blueing, cracks, galling or score marks. I'm using roller tip stamped steel 1.5's at the moment and probably will continue using them when I finally pull the 350 and install the 302, but what if I did go back to the 'O' rockers?