408 hyd roller, too much spring pressure?

Ok lol…your first link is about a slightly hotter than stock cam. You can run ANY spring on that junk and it will be fine.
That 2.3 litre cam that spun to 9200rpm (stock cam???) with beehives was a .575" Schneider – a pretty hot cam for that engine.

Please read this again properly before you comment: Ford Lima 2300 cam help please - Don Terrill’s Speed-Talk