[eschaider]

Just like cam core suppliers, there are only a few credible valve spring manufacturers capable of making high performance valve springs. Almost everyone buys from them, rebrands the springs and markets them under their own naming convention. Two of the three big boys in this game are PAC valve springs and Associated Spring. There is actually a third supplier whose name my aging brain cells can't recall right now.

All three firms will build custom spring designs if you contract them to do so. The biggest problem with going down the custom spring path is that frequently the reason the original spring manufacturer does not offer the design is because current metals technology and heat treat will not reliably support the design.

In all probability the spring you have that failed, as others have already pointed out, either had impurities in the steel that initiated the failure or perhaps it was an il-conceived custom design that should never have seen the light of day.

As others have already suggested you should give serious thought to replacing all the remaining springs with known good alternatives. PAC will sell directly to you. Associated tends to be more of a high quality spring manufacturer whose business focus moves products through distribution under the name of a respected retail name.

PAC is the easy choice. There are a number of excellent aftermarket providers like Manley that provide high quality product. Interestingly the il-conceived custom springs are sold most frequently through a cam manufacturer. Buyer be ware ...


Ed