I ran 7.400 LS (comp brand) pushrods in my 360 without issue (5/16", 080 wall) on a solid flat tappet cam with 1.6:1 rockers, .384" lobe, (edit: adding that they were the Howard's solid lifters with EDM hole) & the comp 26915 beehive springs set up at about 305 lb open load...worked okay for me...