I'm changing my unbushed-lifter-bore, stock RB block from a hydraulic roller to a mechanical roller valvetrain.

I am leaning towards running the Isky 3672RHEZX EZ-ROLL X Solid Bushing Roller Lifters with the .125" higher pushrod seats, so I can run shorter, more ridged pushrods.

I have learned that virtually all mechanical roller lifters slightly uncover the lifter bore on the cam side of the lifter bore on unbushed lifter bore blocks. How much depends on the individual casting and machining characteristics of a given block. I would have bushed it, but I don't really want to tear down the short block to do it now.

Is there anything I should know or need to consider before pulling the trigger on these lifters or on not running a bushed bore for the lifters?

Thanks, guys.

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1970 Plymouth 'Cuda #'s 440-6(block in storage)currently 493" 6 pack, Shaker, 5 speed Passon, 4.10's
1968 Plymouth Barracuda Convertible 408 Magnum EFI with 4 speed automatic overdrive, 3800 stall lock-up converter and 4.30's (closest thing to an automatic 5 speed going)