280/280/108 hydraulic cam - single springs with dampers OK?

Greetings Ford Six Fans,

250, .005" deck height, composite gasket, AL head with 55 cc chambers, currently running Clay Smith 274/274/108 hydraulic cam, 1.6:1 adjustable rockers, and single springs with dampers. T-5, 8" 3.00 open differential being replaced by a 3.80 Traction Loc.

I purchased a new 280/280/108 hydraulic cam from a forum member, and plan to install it along with milling the head to warm up the engine a bit more after my T-5 swap and upcoming 3.80 Traction Loc.

The specs for the two cams are:

Current:224 degrees duration @ .050 .480 lift @ 1.6:1
Future_:231 degrees duration @ .050 .512 lift @ 1.6:1

Even with the new cam, I will probably never rev my engine past 6,000 RPM at the most (I have an MSD 6-AL with a rev limiter I can set just above the HP peak; currently the rev limiter is set to 5,500 RPM per my dyno results).

I know that dual springs were originally recommended for this cam by Classic Inlines; how necessary are they? It's interesting to me that on the Vintage Inlines page that discusses the new version of the AL head, the bind height of the dual springs is seen to be same as the bind height of the springs with dampers, and the recommendation for dual springs vs. single springs with dampers is based on cam duration. Can someone help me understand why more spring tension is needed for longer duration? I would expect that necessary spring tension would be related to higher lift, not longer duration.

Thank you,
Bob

Bob, as long as the seat pressure is equal & open pressure is equal should be no problem. Check for coil bind since when Mike just installed stock length valves it should be checked.
The valves should be .060" longer so a camshaft with a lot of lift will not cause the above problems.
The longer valves also gives you a wider selection of valve springs.
The CI heads still flow good up the .600" of lift. But you are getting into solid lifter area.