NO he doesnt need a particular GPI weight for an arrow, you need a correctly spined arrow, overall arrow weight means nothing, its only a personal preferance.You need something in the 8 gr, range. I shoot 60 pounds with a 27 1/2 inch draw. I use gold tips in 5575 and carbon express maxima hunters 250
Both shoot well for me.
Gold Tip 5575 weighs 8.2 gr. per inch
Carbon express maxima 250 weighs 7.3 gr. per inch
Carbon express maxima hunters weigh 8 gr. per inch
ill bet you can make field points fly ok but when you screw on BHs i see some issues, these 340s might be stiff but you can try 125g points first. Try em out first and swap if you need to after you try your .340's27" 60#, I have been shooting beman 340's 9.3 GPI, 26.5", Should i go down to the 400's, or maybe a differnt arrow??