Anderson window balance replacement

Hello,I am looking for balances for an Anderson Narrowline window 3046 from 1983,I did take out a balance and got some numbers off of it,they were very hard to see,but this is what I wrote down E 54 9#27 5 83 . Also had 11600-2 stamped on it.Would you be able to tell me what parts I need .I would like to replace both balances on two of these type of windows,Thank you