Arrow tuning for a non center shot bow

[lenador]

I've been reading quite a lot about arrow tuning prior to finishing my Osage bow. I'm planning on trading hunting this season and I've been trying to get my 40# red oak bow tuned for a batter flight and I really couldn't find much about bows with a severe non center shot. My red oak is a bend through the handle  bow and currently has no rest but I'm adding a leather rest as we speak to furter hone the arrow flight in.
I'm planning to purchase an arrow test kit and field point test kit from 3 river archery but some I fo I've read for non center shot is leading me to think that I need a much more under spined arrow and heavier tip to get my dynamic spine higher. I'm having a hard time finding a spine test kit with a spine lower than 600 and I don't want to use tip weight to fix an overspine and have my arrow be heavier than I need.
 So, do I
A.drop to 600 and tune it in with tip weight
B. Find a 700 spine and order it separate
C. Give up and wait until my Osage with a rest is done?

[Badger]

 Tuning is something that has to be physically done. But for a close starter you might try this. You have a 40# bow so you start with a bow with 40# spine that is 30" long with a 125 grain point. For every 1/4" off center you remove 5" spine. For every 25 grains of point weight under you subtract 5" spine and for every 25 grains pt weight over you add 5# spine. In your case I would start with an arrow with 25# spine. I bet that would get you pretty close..

[lenador]

Tuning is something that has to be physically done. But for a close starter you might try this. You have a 40# bow so you start with a bow with 40# spine that is 30" long with a 125 grain point. For every 1/4" off center you remove 5" spine. For every 25 grains of point weight under you subtract 5" spine and for every 25 grains pt weight over you add 5# spine. In your case I would start with an arrow with 25# spine. I bet that would get you pretty close..

I'm using carbon arrows so they are spined in the hundreds. Honestly don't know what the comparison is. I've already started physically doing arrow tuning but currently the lowest alike I have is 500 and if I buy a test kit the lowest they come is 600. This is why I want to buy a test kit of arrows and points so that I can tune my arrows. Currently 500 spine and 150 grain at 28" are falsely showing over spined. This is what led me to look into tuning with a bone center shot bow. My arrow flight is showings early over spined but I know they are not. I can shoot a 350 with the same result and Ive been informed bows that are not center shot have a false over spine when tuning.
 Anyways without going down that rabbit hole I'm trying to tune my 40# bow and it's showing over spined with 500 spine and 150 grain tips and I'm trying to find an arrow test kit that goes from 700+ instead of 600+ so I don't end up with 600 arrows and super heavy tips.