What is the correct degree for the timing on a 1990 Chevy K-Series 1/2ton p/u with 5.7L (4WD, automatic) and is there anything special I should know about setting this? How do I stop the advance to set the timing? Thanks.

On Hondas, you jump the Service Check Connector with a paper clip. This prevents the ECM from advancing the timing. Maybe someone else will chime in with regards to your truck.