S540 tib conversion problem

[Yogi_fish808]

I have a narrow 533 I use with 50lb but I use tournament ande  on it so it really breaks at 50 lbs. I would think 60lb should be ok as long as you use an aluminum spool. Maybe someone would know at what point the side plates would fail. I would think that would be the weak link

I wouldn't be worried about the sideplates on a 500 series blowing up in regards to line size. Here in Hawaii its not uncommon to see 60-80lb mono, 150lb shock line and piano-wire leaders used on a 546-550 size and land very large GT's in deep water reefs. If you use a 5+1 drag kit it might be best to stiffen things up with a tiburon kit if your reel has graphite bars/base.