318/360 heads,with thumper cam

Thanks,are the pistons still ok to use ,even after better springs,or are they kinda on limp mode now,like maybe its no good,find a different block,or better pistons type of thing?also,the engine ran very well before,and i might add that i never really ran high rpm's since i swapped the cam,only a few steps on it,and starting it for the family,and friends,so could it be from the old cam,idk if the cam i pulled out of it was the original.