Partial Mash - Efficiency?

Hi All,
I haven't done an extract batch in a long time and I am a bit rusty with my recipe formulation.

I am going to do a quick partial mash in my kitchen tonight and I will be mashing 4.5# of grains.

I am plugging my ingredients into beersmith and I am not sure what I should enter for my efficiency. I don't think that the grains will be very efficient in the muslin bag that I am using but I have no idea what to enter here.

The other question is, if I adjust my 'brewhouse efficiency' in beersmith, will it only apply to my grain bill, or will it apply to all fermentables including the extract?

Here is my grain bill for a red ale:

3.3# Pale LME
3.5# Pale 2 row
.5# Aromatic malt
.5# C80

I would like the gravity to be around 1040-1045ish

Only your grains, do 60% and even if you get higher it wont be that much

Sounds good, that puts me at 1043 which should do the trick!