my current set up is bob lee 54 pounds my draw is 28, im shooting 30 inch gold tip blems 400 spine bareshaft flys great with 145 grain head, im trying to get more grains out of my set up even if i cut arrow to 29 icnhes the arrow tunes good to a 200 point field tip that would put me just over 500 grains, im trying to be around 550-600 what do i do go down to a 340 spine and tune to a heavier head?

You could remove the aluminum insert and replace with a 50gr or 100gr brass insert, in the 400s and try it. Never know might not need different arrow shafts.

I'm with Shadowhunter, add 50-100 gr to the front either with a heavier insert or field point and see how they shoot before getting new arrows. My 51# bow tuned great with full length GT 400's with 250gr up front. Total arrow weight is right at 600gr.

At 29" you should be able to get close to 300 grains up front to fly well.

Lower your brace height to help compensate for the weaker arrow.

I have the same BL setup and shoot the GTs cut to 29.5 with a 100 gr insert, 175 gr point, wraps and four fletch. Weights about 610-620 gr and flys like a dart. I also shoot GT 35/55 with a 50 gr insert and same combo setup for 550 gr. Little flatter shooting.

Cutting an inch off a carbon shaft is a LOT, hard to believe you only need 55gr more to tune.

i will try it again today and see what i need for the 29s this is all based on bareshaft straight flight for the results

If you bare shaft great with 145 and have some different weight tips you might find the right combo. A 1/8 -1/4 cut at a time will change things more than you think. also you can add weight tubes/or cord to the inside of the shaft to get the weight up.
My Silvertip57@27 & Blacktail 53@27 I use 3555(500) 291/4 2inch footing(2117) 50insert 175 point wraps 3 5inch feathers 536 total  

https://vimeo.com/70422708   this may help

one inch does make quite a bit off difference im showing a tad weak with 250 grain head and standard insert, thanks alot guys, how many grains varies cutting a half inch usually?

If they are GT traditional classic blems, they show 11.4 grains per inch.....so a half inch is 5.7gr.

i mean taking the half inch of how much more weighht do you usually have to add to make them fly straight out of the 30 inch arrow 175 grain is slightly weak which is good 250 showing tad stiff at 29 inches these numbers sound correct?