Timing Chain-moving the Crank

The difference between the new set and the replacement sprocket you got is the old set was an aftermarket type with 3 keyways cut on the crank sprocket to allow you to advance or retard the cam timing. I think the new part will work even though the listings didn't include your 1970 318. An LA timing set is an LA timing set as far as function. It just doesn't have that adjustment feature your original set had. You just turn the crank sprocket to line up the marks and your good