new SS valves vs stock

[recky2000]

I just bought these new SS valves and they are supposed to be stock replacement! I noticed they are much taller than the stock ones. Do you think I received a wrong set!

 

[oldmodman]

The valve stems are usually ground to the correct installed height after the seats and valve faces are ground. After grinding the valve stems usually need to be ground due to now being too long.

That's why they come longer when new. But not always. You can always order them with a specific delivered length.

With pushrod engines this is not as important unless it affects the valvetrain geometry. With our engine it is much more important due to our limited adjustment of the automatic lash adjuster base.

Before returning them talk to your head builder.

 

[ctgreddy]

^ agreed. That's why if you look at the lock groves they're in the same spot. This is why you really need to have headwork on these things done by someone who knows these heads as its much more critical on things like this than older stuff.

 

[SlowSVT]

There is no reason to replace the OEM valves with stainless unless they are unusable (I would buy new OE valves if they are cheaper then aftermarket valves). If your old valves are still good and you can return the SS valves for a refund you can put the money to better use. Oldmodman is correct, then stem height is determined when the valve is seated in the head.

I'm not sure why Ford chose to move the retainer down in the stem requiring shorter springs. A longer spring is better than a shorter one.