318 pulley questions.

[charger72]

I have a 74 pickup with a 68 or 69 318 in it. I have the a/c pump on it, but to change make it so I dont have the a/c pump I have to change pulleys since I have a small pulley on it now. I bought a bigger pulley from a non a/c truck(which is the same on my 72 charger ) but it seems like my crankshaft pulleys are too big. Can I change them to a crankshaft pulley out of a 70's truck? with out affecting anything like the timing?  Hope this made sense.

[Chryco Psycho]

yes , it may slightly change the speed of the alt & power steering but it will work OK