I've been reading a lot on here about the quadzilla getting comfortable on tuning it with the new setup. We are moving to Montana from New Mexico pulling a 30ft trailer with all the house things. I'm trying to find the best tune for fuel mileage without losing too much power for pulling the hills. I'm new to it so any information would be awesome. I have 7x.009 injectors with a s475 lower and a phatshaft upper i can't quite remember the turbo size I'll look it up and get it though. 

with the weight you are pulling I wouldn't be to worried about MPG.  you will be cruising at pretty high load and boost levels and needing a lot of duration to get the twins moving with the little 7 x .009's.  

 

If you have studs then you can run a bit more timing, but I don't think I would be pushing it much past 17* 

Ok I do have studs. When you say little makes me think I should have put some bigger injectors haha I didn't want a ton of smoke is why I went with those. 

Bigger injectors would be good.  A hx35 is the realm of 7 x .009's. Since you have tuning I would be looking at 7x .011's 7 x .010's would also work

 

 

You will need less duration to make the same power

Ok I'll have to order some when I get to Montana thanks for the information on it all. I downloaded a tune from here I think it's called twins with large injectors towing I maybe can tweak that a little since my injectors arnt really large injectors.