You should not be using higway lean cruise until your tune is in order!

With the ECM seeing knock it is pulling timing. Do you here any ping or knock? Have you set the base timing on the distributor? Have you used a timing light to verify your timing in spark table is close to what is on timing marks? My advice is to not drive the car till you find out what this issue is, knock this bad if real can casue major damage!

Yes EBL is big on Thirdgen.org RBob has been hanging out there since before dirt, that's why I pointed you that way.

Hope you get er worked out, always welcome back here to share. Right now you need to be careful till you get these issues in order.