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Thinking about upgrading the cam in my 75. She has a crate ZZ4 that hasn't been modified. I would like to find one that will not require going into the heads if it exists. Any suggestions? TIA
An easy upgrade to the ZZ4 is by using the GM "hot cam" and 1:6 rockers that were made for your ZZ4. GM says it increases the hp from 355 to about 394 and is a direct install with no other modifications and not expensive. I installed one in my wife's ZZ4 equipped 78 about 12 years ago and was happy with it. There are so many cam and rocker options available today it's kind of mind boggling. Depends on how much you want to spend, how much work you want to do and what kind of performance you are looking for.
Last edited by CanadaGrant; Oct 4, 2018 at 10:56 AM.
An easy upgrade to the ZZ4 is by using the GM "hot cam" and 1:6 rockers that were made for your ZZ4. GM says it increases the hp from 355 to about 394 and is a direct install with no other modifications and not expensive. I installed one in my wife's ZZ4 equipped 78 about 12 years ago and was happy with it. There are so many cam and rocker options available today it's kind of mind boggling. Depends on how much you want to spend, how much work you want to do and what kind of performance you are looking for.
That's what I was going to suggest. I've already upgraded my ZZ4 with 1:6 rockers and one day I'll install the hot cam. If I don't I'm going to go with a LS swap.
Same as the above two. I upgraded my ZZ4 with the GM's "LT4 Hot Cam". You can buy it as a kit w/ roller rockers & springs, or you can just purchase the cam by itself as I did and purchase the other components as desired.
New cam for ZZ4
