After the recent engine swap in my '91 RS to 355 Small Block, I know need to update the Knock Sensor. I went and checked at my local parts store, and discovered that in '91 the Knock Sensors are different depending on if you have an automatic or manual transmission in the truck lines. The Z/28 uses the same knock sensor as the automatic truck I guess because there wasn't a manual transmission in the 350 powered Z/28's back then. SO, my question is which Knock Sensor should I get? I figure I'll need the one for a manual truck since my car is a manual transmission car. BY THE WAY, I read the 305 to 350 swap Sticky and didn't get an exact answer from it on which one to use.

 

KS + ESC selection depends if your 350 is equipped with a roller or flat tappet cam. For a flat tappet cam 350 I would use 84-86 Corvette specified parts:

ESC module - GM 16126761 (AC-Delco 216-45) (Old part 16052401)
Knock Sensor - GM 10456287 (AC-Delco 213-325)

For roller cam based 350 I use knock sensor from 92 B-car
ESC module - GM 16052401, 16128261, AC-Delco 216-47
Knock Sensor - GM 10456288 (10456126) AC-Delco 213-324

Please note that GM obsoletes and supersedes part numbers left and right. The after market parts - SMP, Airtex, Wells, etc tend to be generic approximations of original part. Most of the time they work OK, but depending on a particular combination they may not be an optimum combination.

//RF

 

Alright that sounds good. I've got a flat tappet cam in mine, so I'll be goin' with the '84-'86 'Vette stuff. I'm still wondering why there would be two different sensors for manual and automatic transmission car.

 

Those numbers are they for an auto or manual or does it really matter? I found them at Amazon for 81 for the pair

 

Should not make the difference - at least parts cats do not show.

 

They arrived from amazon and there both A/C Delco and shipping was free.