I'm running 37s on a OME J springs, 4.10s. It is my DD. I haven't done any other suspension mods except to remove the rear sway bar. I run Deutsch Tech 8000 shocks with 12.5 travel, rides great in my opinion. Cruise control still holds going through the mountains, and I only have slight rubbing...
I would have the rebuilder check everything( Main bearing alignment, check crank for cracks, check the cylinder head for guide and valve wear, flatness, and spring pressure, and then make my decisions. ) Then you would have good info on what to include as far as machining. Balancing the rotating...
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Rodney Valvebody Flush A440
You should be able to read about this exact thing being performed at a faster speed to reverse flush the valve body. I would start at valve body or Trans pressure testing, I think you have a check...
Put them back in, looks like they had been serviced enough to replace one or two. I would repack and reuse them unless the have heavy play on the spindle(inner race).
Most well sealed engines will stumble or try to die if you remove the cap, because of the instrant vacuum leak. Some engines can cope with the massive vacuum leak by adjusting idle via idle air control valve, some engines have small vacuum leaks already and so its not drastic to introduce new...