Gutter help

[Lph008]

I have a 38ft seamless 5" gutter with hidden hangers to hang. I'm reading so many different opinions on pitch.
There will be 1 downspout, 4/12 pitch metal roof, 1 now stop along the whole length of roof. I'm in Buffalo Ny so we get alot of snow.
I want the gutter behind the drip edge but in order to have the gutter behind the drip edge on the downspout end, I can't pitch 1/2" every 10ft like they recommend

 

[toolmiser]

Can you trim some off the upper edge (of the gutter) on one end so it can be pitched. I hope you are going to use the extra large downspout.

 

[Lph008]

Can you trim some off the upper edge (of the gutter) on one end so it can be pitched. I hope you are going to use the extra large downspout.

It can be pitched, the most pitch I can get over the 38ft is around 1" - 1-1/4" that would still allow the high end to be high enough to catch rain coming off metal roof and also the gutter is behind the drip edge at the low end. I don't want the gutter too high that snow/ice sliding will damage it,