Your rocker arm studs are likely pressed in and the pushrods are factory as well as the rocker ratio. Where people may see a horsepower increase is when they go from 1.5 ratio rocker arms to 1.6. Which gives them a bit more flow on the exhaust and intake because of the higher valve lift. have stamped steel arms on there now and i was wondering how much power i would gain. Source(s): horse power roller rocker arms add 350 small block chevy: https://biturl.im/PMEgS. Nela · 2 months ago. Thumbs up.