[James Montigny]

.

[Darkfuzion]

I would assume those are BTR .660's, they are the most common. They could also be PAC Racing .660's. Also, I think those might be titanium retainers.

[Joshinator99]

Originally Posted by James Montigny

The important part is that they'll hold up at 7200rpm under 20+ lbs of boost.

You might want to have them checked or just get a new set. Keep in mind you lose some spring pressure due to boost in the cylinder. You are kind of rolling the dice…you don’t know if those springs were ever floated previously and it’s kind of a disaster if things go sideways at 7200 RPM…

[KingLT1]

I don't think I would run used springs on a new build.

[James Montigny]

Originally Posted by KingLT1

You put used springs on a new engine?

Bought the heads assembled from TSP.
All brand new at the time.

[Joshinator99]

Originally Posted by James Montigny

Bought the heads assembled from TSP.
All brand new at the time.

Sorry, the original post made it sound like they were used when you bought them, so that’s why King and I responded the way we did.

So that being said, you could have a quick conversation with TSP about those valve springs still being good for your setup at 7200 RPM and with 20# of boost, since they’ll also know the weight of the valves they sold you.