Say you have two prepped blocks, one for conventional .842 lifters and the other for .903's. You have two sets of solid roller lifters - one with pin oiling that fits the .842 block and the other no pin oiling but reputable. Bore, stroke, everything else is the same, just the lifters. Cam won't be considered "aggressive", lift not over .700. Should be easier on lifters than some on here running race engines on the street, not looking for every bit of power (at least at first)
Car is street/strip/cruise, built with parts that can take 7500 without making the driver cringe so hard that he cracks the enamel on his teeth.
Which way to go and why?
If they are both quality pieces of the two I would prefer the 904's assuming the added expense isn't an issue
Larger axle, more load area, less load / sq in,,,, all good things
That said the difference is not huge & for what you describe I wouldn't recommend the extra work
Too many "small" lifters giving good service
But I rarely use any conventional needle lifter anymore either so,,,,,,
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at least in theory the larger diam. lifters usually tend to weigh a bit more but the larger diam roller puts less stress on the lifter, lobe and valve train, its a trade off ,if your running solid rollers and the correct oil system they both will tend to get enough oil to lube the lifters roller, but Id generally select the larger lifter preferring at least in theory,increased potential durability over the minor increase in rpms the lighter weight valve train component MIGHT provide as in an ideal world your not running on the ragged edge of valve train control/stability
you might want to increase lifter oil flow rates if your concerned
While helpful on a flat tappet, especially hyd flat tappet where you cannot run EDM lifters
That modification is very close to useless with a roller of any kind
It does not address the most common point of failure which is not the cam roller interface it is the Axle/needle interface that problems almost always start
The exception where the roller face & lobe go south is usually caused by improper heat treat or the wrong core for the lobe used where you are through the hardface or it is too thin to support the load
Or of course the infamous Comp cast core solid rollers
