Alcoa spiral balance with a white tip

Are you sure the balance tube is 3/8" and not 5/8" in diameter? Alcoa used Series 600 (5/8" diameter) tilt balances. As far as the balance tip- I would recommend moving up to a red tip, since your balance is 30" in length.

If you can, please double-check the diameter measurement.

Take a look at our Series 600 S600-30 Spiral Balance The diameter is 5/8", but it is often times used as a replacement for the 1/2" white plastic tube balance. The red tip option should work with your application.

Let me know if you have any additional questions.