85C20 Fan Shroud Questions/Issues Serp Belt

[1972C10]

Does anyone know for certain The small block fan shroud vs a big block fan shroud differences?

I have a big block shroud i had been using with a 350 and a flex fan and it was close to the passenger side and bottom but didnt hit Thats where my new fan setup is hitting It seems it is larger diameter than the flex fan i had been using

I recently changed over to the Serpentine belt setup off an 89 and the fan rubbed

My options are modifying my exsitsting BB shroud Or buy a Sb shroud and hope it works with my current Clutch fan setup

I dont mind so much the idea of modifying the one but if a buy a new one id like to know that it would clear this setup I have now Because if im going to modify one i may as welll ruin the one i already have rather than buy one then have to make it work.

If anyone has any info on the subject it would be greatly apreciated.