Yes, a set of Isky nodular rocker arms would work great but they are hard to find these days. I kind of regret selling the couple of pair that I used to own since they would come in handy on some street builds.

I don't think or believe that the lifter weight has any bearing on how the valve springs act, live or wear
Dale Armstrong did ,allegedly, some engine dyno testing on weight on the lifter side of the rocker arms by adding weight onto the pushrods back in the early 1970s when he owned and operated 10,0000 RPM speed shop in SO CA on one of his blown alcohol Hemi motors. His conclusion was that the weight he added on the lifter side of the valve train had no measurable impact on the motors HP or where the motor made peak torque or peak HP

Be careful of aggressive hyd rollers....very fun to control. And not worth a bunch of power compared to something smoother with more lift. We would run around .650 at the valve.

Lifter and pushrod weight means nothing, at 5000 or 10000 rpm.

Disagree about an aggressive hydraulic roller, did a small block with Morel std. travel lifters, small PSI dual spring, 615 hp and 8300 rpm

Yes, a set of Isky nodular rocker arms would work great but they are hard to find these days. I kind of regret selling the couple of pair that I used to own since they would come in handy on some street builds.

I know stock stuff runs for a bazillion miles with no worries but lets not go there.

I've whittled down the head selection on my 543. The Eddy RPM heads are heading out for a tasty CNC job. Now, I need to solidify the uppy downy bits that lets the poor thing breathe.

Again, 5300 lb street car built for general hooliganism and the occasional road trip. That means trading off crazy power for longer life. It's also in my best interest to keep this thing under 6000 RPM so the crank doesn't go on vacation.

I'm looking hard at the Hughes 232/236/110 hydraulic flat cam. Teaming that thing up with some 1.6 rockers looks pretty tasty. Lift goes to .571/.582 and isn't too hard on parts. Typical lifter weight and moderate specs open up spring options.

However, I'm tempted to go with a more aggressive hydraulic roller cam like the Comp 236/242/110 .544/.541 which moves to .580/.577 with the faster rockers. The roller lifters are a lot heavier and will put more load on the springs and the rpm is a bit closer to my self imposed red line.

When it comes to racking up the miles will there be a significant difference in longevity of the components? Neither of these cams are radical but the motion is starting to get a little snappy, especially with the higher ratio rockers. I don't mind the price difference of going roller if longevity is there.

Valve spring technology has taken a big jump since I built my last motor. Ovate wire beehive type springs are doing the job of those old dual springs but I'm not sure if the action rate of these cam combos merit that type of thing. Each cam retailer has their preferred spring but there are sometimes better options available.

As for the rockers themselves, are the Mancini's good enough for daily type use or should I drop the coin for Harland?

FWIW, the set Pac 1220 beehives I had with Pac 10 degree retainers gave me 160# on the seat, 370# at .550, and 130-330 with + .050 keepers, on stock 1.875 67 915 heads. Your results could vary, don't know if that's enough spring or not. The pro magnums will be the cheap way to go steel, if you find used iskys they better be mint.... rocker arms unlimited quoted $650 to bush, correct ratio, new adjusters, and new or redone shafts. The comps were $636 when I bought them.