R5 Nut question

[Ollie88]

Will a 1 3/4(45mm) nut width Warmoth Pro neck with a locking nut prep work with a R4 nut instead of the R5?

 

[AutoBat]

Doesn't seem to be the correct Nut for a 1 3/4 nut (R5) according to http://www.warmoth.com/Guitar/Necks/StringNut.aspx
Now will an R4 work on an R5 neck? Not sure, but I don't own a Floyd.

 

[Ollie88]

R5 is the correct nut for 1 3/4 nut width. However I wish to have a wide neck, not wider string spacing. Warmoth neck builder allows for R5 nut only with the 1 3/4 width. So would this R5 neck prep w/mounting holes work with R4 nuts, as this is the nutsize I prefer myself. Are there major dimension differences with R5 and R4 that make the routing unfit for another?