Gas line routing

Unless your cylinder head is a '60-'62 item, remove the spark plug washer rings—they are not to be used with '63-'74 heads, and using them makes the plugs run hot, which increases the tendency to ping.

Also, today's Autolite spark plugs are Chinese junk. Don't know how a 4-cylinder '90 Dakota should figure into it (shouldn't), but swap 'em out for a set of NGK ZFR5N plugs (stock № 3459).