Reel sizes?

Hey, I've been doing a lot of research online, and paying attention to the reels people have been using.

In your opinions, do you think Saragosa 4000F's are to light for the larger species of fish out here? Especially YT and Halibut? They balance really well on my Trevelas, and I really like them, but wondering if I should upgrade to maybe the 5000f?

I've pulled in small football size tuna and some > 30# Striped bass with them, but Just want to make sure I'm not gonna get rocked when I land my first monster YT out here.