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Yes, if the originals don't show any unusual wear on the push rod ends or rocker sockets you can reuse them
There were Roller Rocker kits for these engines, but mixed bag on if they were "worth the money" without doing other modifications with them.
Rollers reduce the friction, and usually opened valves a bit more to increase air flow
On their own you wouldn't notice any gain in power while driving
Dyno tests do show a gain but not really enough to feel it
2001 3.0l Vulcan engine did use TTY(torque to yeild) head bolts, so they can not be reused, even regular head bolts shouldn't be reused, lol.
But for sure the TTY bolts shouldn't be
And if you look up the torque specs on 3.0l head bolts you might find different specs, that is because BOTH regular and TTY head bolts were used over the 22 years this engine was manufactured, TTY bolt specs always have a DEGREE final torque, not a ft/lb final torque
So if you see "turn 90deg" or similar as final tightening thats the specs to use on 2001 3.0l head bolts
If you see "tighten to 68ft/lb" or similar then thats the wrong specs for 2001
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