How far away from the radiator should the cooling fan be on a 68 Coupe w/ 350 and HD radiator?

Im pretty sure the cooling experts will say the fan blade should be tucked into the shroud about an inch or so. If you are not using a shroud, Im not sure. The shroud will improve your cooling alot if you havent given it any thought yet.

Thanks for the reply Click.

Got the shroud in yesterday and will mount it today. As for the fan, I haven't got one yet. What do you reccomend for a stock 350, 4 barrel with M20. I have a heavy duty 4 row radiator radiator, no A/C? Also, how much cleareance is needed between the tips of the fan blades and the shroud?

The stock shroud will hold up to an 18" fan, tho a 17 will also work and leave a lil more room for things to move around. Best would be a 7 blade fan with a thermostatically controlled clutch. The fans can be found, clutch would be an auto parts store item (possibly still avaialable from GM, that would be preferred) for a 68 small block with A/C.

I use a derale 17000 series flex fan, and it also cools VERY well, and is lighter, cheaper, and better looking than a clutch type fan.

What he said :) here's a pic to give you a visual.
cools very nicely even with the A/C.