Both were used on small blocks in 68 and 69.

I think on 340's, they vary with gear and air conditioning options. My 68 340 with coded 3.23 sure grip and no a/c had a Saginaw but it's no survivor. But it was standard bore numbers motor.

I've seen a 68 green notchback 340 in a magazine that looked like a survivor that had a Saginaw.

I think on a clone you could go either way. You can get parts for saginaws easier and imho better units that are more durable and don't lock up with quick maneuvers.