will LT1 or LS1 fans (dual ) work or be made to work on my *( IROC ??

 

yes, the fans really are no different, they just need power & ground like all electric fans.

 

what I mean is , sre the size of the fans similar in size to the rad/are the neded mods strait forward ??

 

factory fbody efans normally attach directly to the shroud,
and it would probably be VERY easy to fit the shroud to many radiators even if they are a little different.
LS1 and L98 radiators are very close in size if not identical.