Difference between these two FMS rocker arms?

I'm going to pick up a set of 1.7 rockers.. FMS makes 2 different sets, one is the Crane/Cobra version ($190), and the other is the blue Ford Racing version ($280-350).. anyone know what the difference is?? All the specs look the same, is the blue set better, or just blue?

Cobra set http://store.summitracing.com/defau...4294925232+4294924497+4294839885&autoview=sku

Blue set
http://store.summitracing.com/defau...4294925232+4294924497+4294839885&autoview=sku
No picture at Summit, but here they are at Mustangs Unlimited
http://mustangsunlimited.com/itemdy01.asp?T1=M6564E351+01&Category=&catkey=74-01

The ones at MU and summit are the same part#, summit just lists them as 1.70 for some reason (they list the crane cobra rockers as 1.70 too and they're 1.72). Of course the tech hotline is closed today.
I'm thinking about running up to MU to pick up a set and some other odds and ends, but all they have in a 1.7 is that $280 blue set, don't know what the advantage is to the other ones..

Here's the specs from ford..

Cobra 1.70 rockers M-6564-A50
302/351W — 1978 and later with production heads. Cast iron and aluminum GT-40 heads
1.70:1
Bolt On
Inline
Same as "Cobra" 5.0L Mustang. These rocker arms have beefy trunnions for extra long life. Die cast aluminum construction.
Dimensions: 2.25H x 9.50W x 17.00D
Weight: 9.30#
PERFORMANCE FEATURES
Reduces friction and horsepower loss.
Increases high RPM valve train stability.
DESIGN FEATURES
High strength trunnion supported by needle roller bearings.
Grade 8 adjusting nuts.
Precision machined from 2024 high tensile strength aircraft alloy extrusions.

The blue ones 6564-E351
302/351W — 1978 and later with production heads. Cast iron and aluminum GT-40 heads
1.70:1
Bolt On
Inline
For stock production cast iron cylinder heads with hydraulic non-adjustable valve train. Does not require guide plates, hardened push rods or pedestal machining. Includes pedestal inserts & bolts.
Dimensions: 2.25H x 9.50W x 17.00D
Weight: 9.00#
PERFORMANCE FEATURES
Reduces friction and horsepower loss.
Increases high RPM valve train stability.
DESIGN FEATURES
High strength trunnion supported by needle roller bearings.
Grade 8 adjusting nuts.
Precision machined from 2024 high tensile strength aircraft alloy extrusions.



So.. aside from shaving .3 pounds... what does the blue set do? Anyone?