you could have a number of things going on , First the clutch fan is a far better choice IF the clutch is good , the fan should be tight when hot . Second make sure the fan is on the right way with the blades cupped towards the engine , did you use the same water pump , a high volume may help ? . I suspect the ign upgrade is where the heat is coming from , , disconnect the vacuum advance & leave it that way , most dist use about a 20* mech timing curve so you want initial timing @16* with total timing at 36* make sure the carb is not lean , check the plugs or install a wideband O2