Here are both arrows with an adjusted IBO of 302. I adjusted the IBO for the 515.7 gr arrow and after getting the results then manually entered in a 365 gr weight for the arrow. What was the predicted speed that you got for the 365 gr arrow? The 289 fps for the 365 gr arrowseems reasonable with your DL and the "stock" IBO speed being 316.

For comparison,using the known settings for my bow I'd be at 265 w/ the 515.7 gr arrow. The Ally has a slightly higher factory IBO than your bow and I have a 30" DL. I got 296 fps out of my bow for the 365 gr arrow.

If the pictures are too small please provide me with an email addy and I'll send a file with all your info.