I’m line-honing a 6.0L iron LS, ARP studs torqued to 60 ft-lb, and I’m fighting a 0.0002 in taper between #2 and #3 mains; mandrel is straight, stones dressed, housing bores heat-soaked. Do you take another light kiss or switch to a finer 280 grit to hold geometry while landing 0.0025 in oil clearance with Clevite H? Running a Sunnen CH-100.
I’d correct the taper with your rough stones first — short-stroke and bias shoe pressure at #2–#3, and flip the mandrel end-for-end to see if the taper follows; ‘280 won’t straighten it, it’ll just make it shiny.’ Once it’s straight, give it a light 280 pass at low pressure to hit size, and verify with the actual H shells torqued since they can nudge geometry a tenth. Do you see the taper move when you flip the mandrel?
Before another kiss, torque the LS side bolts during honing. With “60 ft‑lb”, are cross‑bolts torqued to spec?