Yes, I can see it in the weapons editor list. I checked the article that you linked. I don't know if the coding is a bit different in SF2, but mine in WOV didn't have a Diameter limit or Load limit. 
Here is what was in my F-4C_DATA.ini 
  
  
[CenterlineStation] 
SystemType=WEAPON_STATION 
StationID=5 
StationGroupID=6 
StationType=EXTERNAL 
AttachmentPosition=0.0,0.37,-1.01 
AttachmentAngles=0.0,-2.0,0.0 
LoadLimit=2050 
AllowedWeaponClass=BOMB,LGB,NUC,GP,LP,IFP,DLP,MER,RCN 
AttachmentType=NATO,USAF 
ModelNodeName=pylon_centerline 
PylonMass=32.21 
PylonDragArea=0.02 
LaunchRailNodeName= 
MinExtentPosition= 
MaxExtentPosition= 
  
And, here is the SUU-16 entry in the Weapons Editor: 
  
  
[WeaponData326] 
TypeName=SUU16 
FullName=SUU-16/A Gun Pod 
ModelName=SUU-16 
Mass=772.010010 
Diameter=0.560000 
Length=5.050000 
SubsonicDragCoeff=0.200000 
SupersonicDragCoeff=0.770000 
AttachmentType=USAF,USN 
SpecificStationCode= 
NationName=USAF 
StartYear=1965 
EndYear=1975 
Availability=1 
BaseQuantity=12 
Exported=TRUE 
ExportStartYear=1965 
ExportEndYear=1975 
ExportAvailability=1 
WeaponDataType=3 
GunTypeName=20MM_M61A1 
MaxRounds=1140 
MuzzlePosition=0.000000,2.881000,-0.033000 
LightPosition=0.000000,2.900000,-0.033000 
AimDirection=0.000000,1.000000,0.000000 
EjectShells=1 
EjectPosition=0.319000,-0.171000,0.000000 
EjectVelocity=1.000000,0.000000,-2.000000