After replacing my 305 with a ZZ4 and a ton of other mods I've gotten as much as 8-10 degrees of knock retard on my scanner. The retard starts around 5000 rpm. I've put in the 350 knock sensor to no avail. Does the esc module need to be replaced as well? It's not lean according to my o2 mv.

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I did the same swap and while this doesn't really answer your question it may help(a little). I'm getting into Prom burning and if you look in that section they always say to change both. I hadn't originally changed the ESC module either but I recently did. You'll notice that they do have different part #'s so there must be something to it.

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1986 T-Top Z-28, ZZ-4 Crate Engine, Complete High Flow TPIS TPI, SLP 1-3/4" Headers, 3" Exhaust, Richmond 3.73's, Moser Axles, Auburn Pro-Series Diff, 2800rpm 10" Non-Lockup Conv., 90/10 Front's, 40/60 Rears, Spohn LCA's, LCA's brackets, SSM SFC.

 

I was told to replace both the sensor and the module when replacing a 305 with a 350.I did and haven't had any problems.
My info came from the guys at Chevy High Performance Magazine.
Don't know why, but like ryn28 said,I doubt that gm would make two different part#'s for them if they were the same part.
-Rich-

 

Thanks for the replies. I will replace the esc module I just won't know if it helps until spring.




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