440Source "Stealth" heads, your experiences and opinions

7 degree locks are probably OK if you’re using them in a milder application that is mostly part throttle operation. If you’re running a big roller cam with high RPM you’re likely beyond using those heads anyway. Sure there are instances where people push them to the limit but in those situations the heads are certainly not 'as-delivered' in any sense.

On the build I did, we changed the 7º locks out but only because we changed the valve springs to suit the cam. Even then it was debatable and we probably could have gotten away with using them. If you're not changing the as-delivered valve springs they will be fine.

I'd say the one drawback to Stealth heads is that if you want to run any sort of cam, you're going to be changing the valve springs. Once you're at that point you'd just get 10º locks. 440 Source probably figures that most people will do that anyway. The heads have been $1,000 for years, they'd probably sell less of them if they were suddenly $1,100.