I would just cut down you wedges 1/4". The S400 should play a touch stiffer than an S300 and it's a couple grams heavier, the thing with wedges is you can't hard step them anyways. Hard stepping is putting the 8 iron shaft into the 7 and 9 iron shaft into the 8, well when you get down to wedges the shortest shaft true temper makes is a 37" blank and there is no way of hard stepping it. You can tip a taper tip shaft 1/2" and it will still fit, and this would give you the effects of a hard step but true temper doesn't recommend it. But it can be done if you really wanted to make them the same as your set.

Thanks, Matthew. I figured the hard step would not be an option. Essentially, my 9 and PW have the same shaft because of the hard step.

Regarding cutting the 1/4" off, I think I may need to cut to a specific length instead. Interestingly, it looks like Titleist has changed their standard club lengths at some point. My old DCI 962 PW standard length was 35.5". The new standard length for a PW looks to be 35.75". I adjusted my specs in my original post to take this into account (specs were 1.5" over in 1997, but 1.25" over now).

Not knowing this, I had 1/2" cut off each of my 4 wedges, and now they all vary in length by 1/4" - new ones longer, old ones shorter.

Back to the pro shop for some adjustment. Although, it may just be easier to re-shaft to get the same length and swing weight throughout the wedges. The last thing I want to do is adjust my swing for each individual wedge given that my wedges alternate (48 new, 52 old, 56 new, 60 old).

My wedges are all same length (35") and same lie angle (65 deg).   I have a pretty vicious short game.

I constructed a set of Q3I irons (5-SW) and 600W lob wedge 3 years ago.  The 9 and the PW-LW were all 35.5" with a 64.5 lie angle.  The 9 iron had a 42 gram grip and the rest a standard 52g grip.

What is the benefit of "hard stepping"? (learned a new term today)

Hard step means putting a 5 iron shaft in the 4 iron, 6 iron in a 5 iron, etc. It ends up making the shaft a little bit stiffer. In my case the S300 wasn't quite stiff enough, and the X100 seem to be too stiff. Hard stepping was then suggested by my fitter.

I too do all my scoring with the iron and short game. That's why I want to be sure I get things right here.

Did you have the lie angles adjusted on your wedges? Are your wedges also +1"?

I'm 6'1" and my wedges are at 65 deg lie angle (I have a Vokey 60-07 and 64-07 spin-milled., and a SV Tour 54/12) with standard length.  My irons are Eye 2 green dot 7-PW.

If you are +1 on length, your swingweight is probably about D7 or D8 (1 inch change in length = 6 swingweight points on a steel shaft; this is given that AP1 irons are D1 swingweight with a standard length and CB irons are D2).  The Vokey PW is about D3 and the others are D5 with standard length (your swingweights for the wedges would be be D9 - E0 with +1").  Better golfers can detect 3 or 4 points in swingweight diff.

I did have my wedges all bent to 1° upright when I had 1/2" cut off.

I can definitely tell the difference in weight between the S300 and the S400. I more interested, however, in the length differences. For example, my 48° Vokey Wedge (PW) is the same length as my 9 iron. It should be 1/4" shorter.