Rocker Arms

[85Silverado]

Does anyone know the ratio of the arms on a '84 LE9 engine? Also, what has to be replaced if I buy new rockers? I was hoping to step the ratio up (ex. 1.5 to 1, to 1.6 to 1) and hopefully get a little extra power. What else would need to be replaced or adjusted? Any help and comments would be appreciated.

[Tom]

stock is 1.5
I wouldnt go with 1.6's. MUCH better idea to just pick a correct cam. It will cost the same [$150 for rockers, $150 for cam+lifters] and give more power.

[85Silverado]

That essentially what i wanted to do, but i have to stay within emissions and I'm not that well versed in installing a cam and don't want to tear that much of the engine apart. Ideally I'd want to just buy a brand new crate motor and be done with it tho..hehe

[87 STEPPER]

Changing the cam is actualy less work than changing just the rocker arm's.

Removing the H2O pump, timing chain cover, and the lifters are the only extra thing's you need to do.

If you only do the rocker arms and you go to 1.6 ratio i wolud highly reccomend you also replace the valve spring's this is where it become's more work than changing just the cam cuz the new rocker arm's are longer and will compress the spring's more, to the point where the spring will not compress any more and binding will occure and you will more than likely brake something And the extra power you will gain porbably wont even be noticeable.

I agree with tom you can do a 1.5 ratio cam change and gain more power and spend less money and if you do some research you can select one that will keep you emission's legal

Good luck

[swervin ervin]

I run a CompCams XE268 cam and pass emissions easily. This cam is not emissions legal, but who knows about it but us, right?

I agree, going with a stock cam and only changing rockers from 1.5's to 1.6's is not going to make big power gains. It will probably help a tad, but not worth the effort to me.

I run Comp Magnum roller tipped rockers, and they are 1.6 ratio. I could not tell you if they made a difference over a 1.5 ratio or not. The reason I did it is to increase lift, without raising the duration. Although, it does make the cam act like it has a tad more duration.

Single biggest thing besides a cam to do for power is heads. As a matter of fact, heads are the single best upgrade you can make on any engine. Stock heads suck, especially 305 heads. Personally, I wouldn't waste my time putting too much into a 305. It just ain't worth it.

[79BIG10]

I ahve a ZZ4 and even with that I passed emissions. It's all about how clean the system runs. You could have a totally stock engine that burns rich of course it will fail. But if you have a street engine that runs on 92 and has a good lope it can pass with the right emissions equiment in place and working correctly.