Have a 66 mustang with 289. Engine rebuild 10 years age approx 10000 miles has noched pistons but do not know much more about rebuild. Problem, replaced heads with afr 165 non emmission heads new cam 2122 edlebrock mild cam with .448 intake .472 exhust lift. New lifters,New double roller timing chain, New hardend 6.8 inch push rods. While breaking in cam valve trane continued to be very noisey, after 15 minutes I shut the engine down removed valve covers. The rockers were loose but nuts were still tight. The lifter plungers are bottomed out. It seems the lifter are terminal. Does anyone out there have an idea or reason for this failure.
Thanks
Scott