Tell us what the bows specs are now (cam type, A/A, and what the draw weight maxes at now). Then we can better tell you what you need.

 

Jumping from 2H too 4H limbs will give you roughly 10# in DW 14" limbs will only give you more BH than decrease in DW.

 

I have a Slayer with nitrous C cams and 13"limbs, the limbbsticker says, 50-65lbs.
the specs on the Martin website are for 14"limbs, according to them you need 5H limbs to have the same poundage with the Nitrous C cams.

 

forgot to mention that the 13"limbs in my slayer are 3M

stringlengths, according to the Martin website the ATA for a S4 / 14"mag limbs /furious is 37.25"
I would make the strings and cables to have that ata measurment....so measure the ata and add the differance to the current string and cable lengths.

I estimate that it will run around 70lbswith the 14" 4H limbs