IMO & most engine builders, especially on a performance type build,
will say almost any adjustable rocker is better overall, than the stamped steel rockers...
or if your going over 0.500" gross valve lift adj. rockers are recommended...
I do know guys that ran cams as high as 0.520" gross valve lift
with stamped steel OE style stock non adj. rockers, with no real issues,
but it's pushing the limitation of retaining the push-rods in the rocker recesses...
It frees up the valve train, especially if all the correct parts &
adjustments are performed properly...
You should probably check &/or change push-rods too,
some require a cup & ball style push-rod
the proper size, style & length push-rods {or rocker geometry}
over the center of the valve stems,
is a critical aspect, to get the most out of your combo, lifter preload is also important...
With adj. rocker & proper length push-rod, roller tip or not,
it gives you a way to precisely get the rocker tip over the center of the valve stem,
best throughout the full range of valve lift &
it also helps to set lifter preload {hydr. lifter}
or valve lash on a mechanical solid lifter camshaft,
than it's mandatory, to have the adjustable rockers...
Generally you'll also need hardened shafts too
{most Mopar shaft style roller rockers come with them now},
when going to a roller or adj. rocker, it helps also if you have allot of valve spring pressure,
like required on a high lift solid or roller camshaft application...
If you've had the block decked & heads milled machined/surfaced,
even if you stick with the OE stamped rockers, you should still check lifter preload,
you may have to shim the rocker shafts or get adjustable push rods or shorter push-rods...
Also the OE stamped steel rocker aren't actually accurately a "true 1.5:1 ratio"
they vary from ranging about 1.42:1 to about 1.48:1 ratios,
mainly because of mass production processing,
they are NOT as precise, but fine for mild performance use,
your giving up a little gross valve lift thou...
Roller tip rockers & even needle roller trunions {like on Harland Sharpe}
will free up like another "allegedly" 15-20hp, less friction & heat...
15hp is nothing to dismiss if your building a performance engine,
but it's more about accuracy/geometry thou...
But it's not critical on a street build, but doesn't hurt either...
Longevity may be an issue, some don't last very long...
I've ran Crane Super Gold roller tip rockers on almost all my projects
{I've had a few even bronze bushed} & haven't had any failures "yet",
I did have a set of the Crane {or Isky also makes them}
Ductile Iron Adjustable rockers {non-roller}
like used on the 413/426 Max Wedges, a while back, 7-8 years ago,
they had an issue with a bad batch of adjusters that weren't hardened properly
& broke one after about 100 miles...
Just get a good adjuster replace them if worn...
Make sure the adjusters on almost any of the aftermarket rockers roller or non-roller,
don't stick out of the bottom of the rocker, anymore than about 3 threads exposed "MAX"
or you will have an oil starvation issue in the cups on top of the push-rods &
bad wear issues or early failure
{if to get the proper lash or preload adjuters sticks out too much, it generally means your push-rods are too short} of the adjusters &/or push-rods,
it will also get/cause a ton of metal particles going thru the engine...
Good luck I hope some of the helps
