Any reason these wouldn't work?
Outside Diameter of Outer Spring (in): 1.437 in.
Coil Bind Height (in): 1.125 in.
Damper Spring Included: Yes
Inner spring included: Yes
Spring Rate (lbs/in): 300 lbs./in.
Inside Diameter of Inner Spring (in): .760 in.
Seat pressure (closed): 135 @ 1.750
Seat pressure (open): 285 @ 1.250
Valve Spring Style: Standard
Max lift: .625
Going by the specs on the Comp springs for the ford 3.8, these are .127 wider on the OD than the stock springs which I believe will fit into the spring seat cups just fine. I'm using FRPP aluminum roller rockers (1.7/1) and it looks like the retainers will clear them. Obviously, they are not beehive style springs. I'm also running a 210/218 cam with .58" lift at 1.7/1 ratio so these should never even come close to coil bind.
Specs on the Comp springs for comparison: (from here
Part # 26918
O.D. 1.075 1.310
I.D. .650 .885
Seat Load 125 @ 1.800
Open Load 367 @ 1.150
Coil Bind 1.100
Rate (Lbs./In.) 372
Titanium Retainer 762, 772, 788
Steel Retainer 761, 774, 783, 787, 795
Cup Seat 4705