Hughes "retro fit" lifter not pumping up!

i've got motors that run daily , no rattle , some can sit for months , no rattle . but this 340 nothing cam and springs , has rattled since fresh start up , after a nights rest , drive it all day with starts , through out the day , not a rattle once . i do understand when spring pressures are out rages , but i've run motors with super high spring pressures that killed lubes on cams , yet never rattled the lifters from setting over night .