Is it imperative that the knock sensor get switched over with the swap? Also can an LT4 knock module still be used in the OBD1 PCM?

Also is the tachometer signal different between the two?

Thanks

 

Yes, you absolutely have to switch the knock sensor unless you modify your PCM so that it works with the current knock sensor. If you don't, you car will set an SES code and retard the KR to max causing very poor performance.

The LT4 KM can be used with OBD1 PCMs.

Tach signal is the same except on Impalas.

 

Beautiful, thanks for the concise explaination madwolf.