If these are indeed crystal type grains for steeping,then steeping them att even 155-160 wouldn't be a bad thing. Just don't go over 170,or you start leaching tannins from the hulls.
I've steeped in 1.5 gallons of water for 20-30 minutes,30 being a better time. I even sparge the bag of grains to get it up to 2.5-3 gallons total boil volume. Then right before that boils,you'll get the foamy hot break for about 3 minutes. Stir down & spray with water bottle to keep it from boiling over. Then add half a 3lb bag of plain DME to the boil for hop additions. Add balance of DME & all LME at flame out to keep color lighter & no twang.
Everything works if ya let it-Roady(meatloaf)