351 vs 390

Question

I'm 50/50 if it's a 351 or a 390 model. The flanges are pretty worn, but it's less than 1 1/8 but a little over 1. 2630 bs/ap is stamped.
I need to order bulk and didn't want to waste the 20 bucks in shipping and returning if I get the wrong one.

Casey · Accepted Answer

Hello,

As long as the shoe depth measures over 1", the S390 would be the way to go. The bottom fitting can wear down over time with normal use, which could be why you're coming up a bit short. Also, be sure not to include the metal tab at the end of the measuring tape. If you still have doubts, you can check another window with the same balances to be safe.

If everything checks out, you would need the S390-27 with 2630 strength options. Thank you!

How to measure the length of the Series 390 channel balance.

Close up view of the S390 balance shoe.