Should I power up my Lapras?

Yes power that up, even tho it doesnt have 80+ ivs, it has the best defensive moveset. That lapras will be awesome for gyms.

Whatever movesets it has, a Lapras is still a Punisher to Dragonite. You are so lucky to have this one. Just power him up all the way to max now and enjoy your fights.

I'd probably power it up since I dont have a Lapras, even though it i encounter a Dragonite about once a month. You've got a nice, rare poke and candies.....

Those IVs are still very solid and the base stats of Lapras are so good that even lower IVs are still good Pokemon. Power up!

Best Defensive moveset, ok IV.

Go go go!
The place for this one is in a gym.

Try Dewgong, Cloyster of DB/DC or DB/DP Dragonite to attack Dragonites. Or wait for a Frost breath Lapras. This lapras will kill 2-3 dragonites when lvl30+ but attacking with Ice shard, is not fun at all. IT is slooow

Best defensive moveset with decent IV. It's definitely a great defender for any gym, but will also be a great attacker against a Dragonite even though the moveset is not optimal for offense. You should definitely power it up, congratulations.