whiteLS1

iTrader: (15)

i was thinking about buying them bare so i could put dual springs on them. but which dual spring will go right on the with no work done. and where can i get valves for them?

or should i buy complete heads and just sell the 918 springs that come one them.

steveb

Give TSP a call, they can take care of you.

vettenuts

iTrader: (4)

First, they don't come with 918's. What is your spring requirement for lift? The out of the box setup is hard to beat, the springs are beehive PSI springs with titanium retainers and machined locks. The valves are drop forged and are pretty light, 98 grams for the intake.

If you buy the heads complete and are very careful on disassembly, I might be interested in the Dart springs and retainers you remove. The springs are nitrided though, so you can't scratch them. You must use a spring tool that pushes down on the retainer like the big "C" clamp type of tool.

whiteLS1

iTrader: (15)

oh i thought i read somewhere they come with the 918's

CHRISPY

They are 918 springs. Dart buys the springs from the same supplier that sells them to Comp OEM

just-a-z

iTrader: (25)

https://ls1tech.com/forums/generation-iii-internal-engine/437768-dart-heads-just-have-let.html
This should help you out a bit

vettenuts

iTrader: (4)

They are not the same springs. Spring rate on 918's is 318 lb/in, on the PSI's it is 360 lb/in. PSI springs are nitrided, 918's are not. In my opinion, these are likely better springs than the 918's. These springs are also sold by Isky as their "Tool Room" springs, check them out there for more information. Also, I think a lot of the offshore boating guys are running the PSI springs, not sure if it is this particular springs, but that is a much more demanding application.