Did you pull the dizzy and prelube the motor before fire up? Death of a flat tappet cam set is NOTORIOUS now days! Just is. Every precaution you can take gives you a % increase in success. Common KNOWN + 's are
Assembly lube, break in oil with HIGH ZZT, pre-lube before fire, immediate filter inspection after fire up with oil change to high ZZT oil, OCD type inspection of EVRY lifter. ALL these combined give you a 75% chance of survival rate .....up from the %50 chance.
