Was getting a super deal on supertech dual springs and valves, but my machinist is advising me against it.Says from his experience they loose spring rates very quick and the valve design looks weak,now i'm thinking for all motor application how well would they hold up.I'd prefer hold on and just get some manley's and not have to worry about it.What do you guys think.This is for my lsvtec build,no boost.

 

Never heard anything bad about supertech valve train. I run ferrea myself.

 

Tons of people use supertech springs and retainers. Never used there valves but seen good and bad from them.