What’s an equivalent or upgraded spring for a 575sci? Can’t seem to find the 24-13455T spring, and it’s also pretty pricy at $35 a piece.
stock cam and everything else.

whats the spring rate

The old springs measure about 340lbs/in, springs have around 400 hours on them, not sure how worn they may be. I see plenty with a similar rate but these seem to be an odd size with an OD of like 1.45”, would rather not buy new retainers.

Hi, I was wondering if you found a replacement for the 24-13455T spring? I have found myself in the same predicament, and I am having a hard time finding new springs to replace this NLA part. Any advice would help, thank you!

For a stock cam, you can use aftermarket 575 SCI valve springs with similar seat pressure. Make sure the spring rate matches to avoid issues.

Quick search i found this.
Hope it helps:

https://teaguecustommarine.com/flat-...8vE2aMU4QIR9Dc

Yep, I run those also on the HP 500 and 500 EFI