I shoot the CX heritage 150's. These are advertised at 10gr per inch. 29" arrow (290gr) + 50gr insert + 125gr point = 465gr. You could then add the 3gr per inch weight tube at 27" would add another 81gr giving you a grand total of 546 grains not including your feathers, nock, glue, and paint. I'm not sure if you'd need the 150's or the 250's for spine, but the 250's are 11gr per inch. Shawn should be able to set you straight on the spine aspect, but those weights should be attainable with weight tubes.