Are you still having issues with fan clearance? I got the same probs with an aluminum radiator, and a small block in my 67 cuda. Dual fans are not the solution, even running dual 10" spals. Ideally a single large fan and shroud is what you need
My solution is a hayden #2765 fan clutch for a 1990 jaguar XJ6 with inline 6. Rock auto $30 And an 18" fan blade assy designed for a fan clutch. Flexalite makes an 6 bladed fan #5718 for $37 through summit racing. Or a 19" diameter fan #5719" This will bolt to the jag fan clutch, and the jag fan clutch will fit your mopar water pump. The hayden fan clutch comes with a centering bushing to center up the jag fan clutch for a non jaguar application. This clutch is approx 3/4" shorter than the stock mopar application. Add a nice fan shroud and your done.
I can check my spacing from my pulley face to my radiator, and give you the dimension i have. But with a small block i may have a little more room to work with.
Matt