valve springs

Is there any advantage to use lower pressure on the exhaust spring than intake due to blower pressure? May have been done fore saving treads in the head? AJPE Billet Olds
Ex. int. 425 ex. 350-375

 

spring

It has to do with the weight of the valves, rpm and boost...

We run bbc with ty valves @440 on the intake and 380-400 exhaust (one season old intake springs) rotate spring.

 

On our hemi it seems like we always float the exhaust first (after three runs) I put them all @ 2.050 with a new set of manley triples I get 485 to 465 on the pressure tester. Ive always put the stiffer ones on the intake but I was thinking the intake closes 70º after bottom dead center when the piston is coming back up and starting to push compression. When the exhaust closes 30º or so after top dead center the intake has already been open 60º or so pushing boost @ the back of the exhaust valve.

The intakes are probably floating too they're just farther from the piston when they're closing and dont leave marks. They are not likely to float open. Maybe its that .509 exhaust lobe dragster cam Norm Drazy warned me about.