Fan to Radiator Clearance

[Hoogah]

I've taken my radiator to the local radiator shop to be re-cored. The radiator man reckons that the frame will allow me to have four rows of tubes, which I'm thinking of going with.
Now I can't remember how much clearance I had between my aluminium two-blade fan and the old radiator core. Is a 4-row core likely to reduce this clearance too much? He tells me that it will be 54mm (2.13") thick. A 3-row would be 46mm (1.81") thick.