do you think .300 spines would be better for my set up, than .400?

I know it was suggested to use .360 spines.

I'm thinking about getting a chrono, and maybe in a bit I'll check back with some updated info. but considering having new arrows built.

I'd like to shoot 70# with my drenalin 28" draw 65% let off.

28" arrow shafts, 100gr broadheads.