I have a 66 C10 with a 350 with a radiator mounted fan but no fan blades on the motor pully is this enough air for the cooling?

...if you're sitting in traffic, this bad boy WILL overheat, that;s what those silly fan blades are about. Obviously you haven't got air conditioning...I had one of these, the six-cylinder was replaced with a Chevy 400, steering was difficult (really needed power steering) the gas tank was sized for the 6 (was too small)....you could screw around and remove the thermostat, but really needs to come up to operating temperature to run correctly....go to the junkyard and pick up a new/used old c/10 pickup fan blades....don't be lazy, this IS important. You can't count on freeway driving constantly and will be stuck without air flow and will overheat...such a silly thing will cost ya, if not tended to~

both my sixty six Chevies had problem with the rear differential (pumpkin)...get some pumpkin shims...you'll need them~

engine has to come up to operating temperature 195....anythings else will confuse the combustion process~

"the engine starts to run and idle ruff any ideas?" -- check the choke. It might not be opening when the engine warms up.

Does it have aftermarket in line fuel pump? If so is it fed with long lengths of rubber fuel line or old rubber fuel line? Have seen rubber fuel line collapse under pressure of in-line fuel pumps. Would crank and run good for a few minutes then would starve for fuel and run and idle rough. We replaced with hard fuel line and problem went away.

no dandyoun it's a '66~ low pressure mechanical pump driven off the camshaft~

Well we upgrade our old motors with electric fuel pumps. Thought he might have too.

electric fuel pumps are a FIRE HAZZARD if not properly wired