pittsburghracer said

I never test the pressure as delivered because I set them up as per customer’s wishes. I think it was JPar that said they were on the light side of advertised pressure. I’ll be tearing down a set of hydraulic roller spring heads today and I wish I could take the time to check some for you but doing it right involves measuring spring heights then pressure and I’m so backed up with work I can’t take that much time. I do know the last set I tore down had six hardened thin shims under the springs.

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Bewy said

While I would happily buy Chinese made cyl heads, I would buy them bare. I would not trust their springs...or valves. These two components are under tremendous stress & it is most important to use known, quality parts. If they fail, they can do a LOT of damage.
Agree with Ken, 120 lb on the seat, 300 open, less than 0.525" lift should be ok. 145 lb on the seat is getting into roller cam territory.

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