Lunatic valve springs frustration!

Unfortunately, even when you read everything...... you can still end up with the wrong stuff.

The cam companies should put a disclaimer in the catalogs stating that the “recommended components” are listed for the popular versions of the factory heads only.
(And usually...... the most generic version of a particular head.
Not a somewhat oddball version....... like.......a 318/360 SBM truck engine that uses exhaust rotators and very short springs on the exhaust.)

Many times aftermarket heads can have installed heights that are different enough from the factory heads that the recommended parts list ends up being completely wrong, along with the fact that they often use valves with different stem diameters than OE.

Case in point....... I have some SB Ford heads here.
Lunati roller cam was bought along with the matching component kit.
Motor was put together and had made passes at the track....... with the results being less than expected.
Heads show up here, I don’t know how or why the heads have the springs they have on them....... but I pull one off, measure the installed height, test spring...... it’s about 132lbs on the seat.
For a .640 SRC. Not good.
They are aftermarket heads.
The installed height is .130 taller than what the spring is designed for.
The spring is designed for the stock heads.
It’s the wrong spring for the new heads.

Sometimes....... you need to assess what you have before ordering the parts.

Like, the SM SBM heads.
They have at least .100” more installed height than a stock SBM head with a stock valve/retainer/locks.

So, when you look in the Comp/Lunati/Howard’s catalog for the recommended springs to go along with the cam you’re going to buy....... just know that the recommended components are based on you having stock heads........not aftermarket heads that have a taller installed height.

Anytime you replace something on the heads(or the heads themselves) that isn’t an exact duplicate of the piece you’re replacing....... just assume it will have an impact on other components...... until/unless you verify it’s doesn’t.
That means springs, retainers, locks, valves.......and even the castings themselves.

As Jim said....... it helps if you’re smarter than your heads.