beehive valve springs

[Crabtree]

What was the first year that the valve springs were changed to the bee hive style.
What is the seat press for the oem springs (beehive)
What is max lift for the beehive.
If running the 54h cams or the se251 cams, would it be necessary to change out the springs
or would they work as is. Thanks for any info.

[Don D]

First year 05
about 125# on seat
Coil bind is not an issue for the late heads under .600, adequate spring pressure to control the valves is. Either of the grinds you mentioned will work with the beehives with the typical valve set up. The springs can be shimmed slightly to increase seat pressure