Snowman, the motor should be sitting with carb/manifold at level. The fan should then arrive at parallel to rad or possibly slightly angled up. Very slightly. If you are still in the mock up stage, fix that. Your 3/4 clearances are OK. Your questions are electric fan issues and rad clearance. If you get the rad clearance to 1/2 min, I guess the electric fan is not necessary. So let us know the clearance to rad with mechanical fan blade/water pump pulley if you need any more opinions/suggestions. Be sure to always check your level tool for accuracy.
The way you do that for horizontal accuracy is: put it on a stable surface and read the bubble location to reference marks, no matter where it settles. Then rotate the level, (keep it on the same foot print of the surface), 180 deg and see if the bubble is at the same place, only on the opposite marks. The rotation of level is about the vertical (Y) Axis. Just spin it like a top in other words.
Vertical bubble accuracy check is same way on a wall.
I know, everybody has a digital level or their iPhone app......but me. Whatever.
