UTG and MP2 are loose/passive as is table.

Party Poker No-Limit Hold'em, $ BB (10 handed) Hand History Converter Tool from FlopTurnRiver.com (Format: FlopTurnRiver)

saw flop|saw showdown

Hero ($30.83)
Button ($67.72)
SB ($3.92)
BB ($23.75)
UTG ($43.13)
UTG+1 ($16.01)
UTG+2 ($10.65)
MP1 ($25.35)
MP2 ($24.38)
MP3 ($25.25)

Preflop: Hero is CO with 6, 5. SB posts a blind of $0.10.
UTG calls $0.25, UTG+1 calls $0.25, UTG+2 calls $0.25, 1 fold, MP2 calls $0.25, 1 fold, Hero calls $0.25, 1 fold, SB (poster) completes, BB checks.

I've been trying to open up my range of hands in LP so with multiple limpers at a loose passive table I make the call with position.

Flop: ($1.75) 4, 7, 3 (7 players)
SB checks, BB checks, UTG bets $1, UTG+1 folds, UTG+2 calls $1, MP2 calls $1

How much to raise in order to make it +EV longterm?