I can guarantee you that if the seat is in the same place relative to the bottom bracket as it was before, whether the seat tube is 73 or 74 degrees makes absolutely no difference whatsoever. It's just a support for the seat. With a 74 deg seat tube, you won't be able to put the same saddle quite as far back as you would have with the 73 deg seat tube. But that won't matter at all unless you already did have your saddle all the way back on that first bike. How are you measuring where your seat is? Not by where the seatpost clamp is on the rails of the saddle I hope - because since your seat tube is one degree steeper, it won't be in the same place as before. Are the crankarms the same length as before? Maybe it's your handlebars that aren't quite in the same place as before. Is your saddle level?