If this motor has stock Mopar 340-360 iron heads you will probally find that the motor likes bewtween 30 and 32 degree total timing If alumimnum or after iron market heads I like to have 16 to 20 initial on the street and always time the distributorfor for total and live with that initial, the motor will not detonate at idle with less initial but it will detonate at higher RPM with to much timing, IHTMS. One thing to keep in mine when setting the initial timing is if the motor wants to kick back against the starter retard the intial until it doesn't kick back. Also make sure your timing marks on the dampener and actual TDC are the same