[GTO-relic]

Originally Posted by performerrpm

I'm pretty sure both of these are pretty close as far as quality goes. I had the ultras set aside that i was gonna and will use but i wondered which set would work best for solid roller use...say 650 ish # open pressure?.
not sure how great a deal it was but today i went to go order the last set of hs s6001-15 that summit showed in stock yesterday and bam...someone done bough'em.....in my google quest amazon showed 3 sets in stock....but recomended a new but open box set for 268.00....i kinda couldnt not jump on that deal.

the old original Harland Sharpe rockers can't be used easily with a big roller cam spring retainer, the retainer and spring will hit the underside of the rocker.
I bought a set from old man Mr. Butler back in the 1990's, he had mocked up a motor with them, and they hit, so he sold them to me on the cheap back then. They had tiny horizontal marks in them on the valve side underneath. I used them on a RA V 455 tunnel port motor with big retainers and springs, they did the same thing. So I had to laboriously hand clearance every single rocker arm, to the larger retainer size, and cut/try until they didn't make a mark anymore underneath- grinding away the mark with a mini air grinder, and trying again. takes a LONG TIME to do all 16. the cam was a 250 @ 050" solid with .560" lift w/1.65's, smallish cam but they still hit.
they will work just fine with Pontiac factory diameter springs and retainers, or aftermarket the same dimensions.
if you want a rocker that fits everything get the Crane gold