The tips being in the middle is not of any significance whatsoever for a roller rocker, as far as geometry. Scrub pattern width it is the most important thing on that side of the rocker.
The springs are obviously not the original Edelbrocks, which are 1.460" OD and 1.80" installed height; stock SBM is similar OD. So the rockers hitting the springs is due to the large OD springs, not the rockers per se. Retainers/locks may be changed too.
Had the same spalling problem with PRW PQ rockers with needle bearings on shafts that were supposed to be hardened... but like yours, they were not. I've got the parts to convert them to bushings. The needle bearings with those PQ rockers were cheap ones, with rollers spread far a apart, not really designed to for the loading, and which I suspect you get with a lot of foreign made rockers. An oscillating motion also tends to push the oil out of the needles, per info form needle bearing mfr's, so is a lot harsher use than rotary motion in the same direction like for a motor shaft.
