I inherited a 57 Super 88 371 J2. Engine recently rebuilt but apparently used original rockers. Has new hydraulic lifters. Has valve lifter tapping noise on passenger side. Pulled valve cover and found slop in front cylinder intake and exhaust valves. All others tight with no lash. Pulled rockers and found both worn badly where on push rod side (pic attached). All push rods look good.
my questions are...
1) Should I just replace the 2 bad rockers?
2) Replace 2 bad rockers and push rods?
3) Replace all rockers and push rods?



2 worn rockers at top of photo. All others look good like the bottom one in the photo.

 

Choice # 3 .
If two rockers are worn that badly , then the rest are well on their way to being worn out .
Rocker shafts should be replaced in conjunction with an overhaul anyway , because they trap sludge .