I’ve built mostly 3wt fly rods for fishing for trout in Arkansas. I use a 3wt 9’6’ sage one as my go to. I find I fish a
Midget so far down from me that I my hook set is a little aggressive and moving to a 3wt helped me lose less flies. A wise fly fisherman told
Me a 5wt 10 ft would achieve the same thing but make mending and casting much easier. It’s been a while since I’ve been in the market for a blank so recommendations would be helpful. I’d hate to spend over $200 since I’ve not built a rod in a couple years. I’d hate to mess up a $400 rod.

Thoughts?

Jason,
I don't think that is an accurate statement . I think you have to take the blank's properties into the equation.
I have built a lot of 10'0" fly rods - albeit not 3 wts. Mostly 6-8 wts.
However - some badly designed (in my opinion) are willowy and are not good for much - unless you like that.
In my experience with CTS blanks a 10'0" blank has the same flex profile but will be able to handle heavier line weights because the taper is continued aft.

I guess a 10'0" rod will allow you to mend more easily - but it will have a noticeably heavier swing weight that I do not enjoy.
Herb
U.S. Distributor CTS Rod Blanks

I believe he specified a st croix rod, but looking through their blanks, i must have remembered this wrong, as I don't see a 10ft St Croix blank.

Jason,
Not saying your wise old friend is wrong, but in this case it's the singer not the song.
The rod is incapable of overcoming the faults of the angler.
True a longer rod put's you at less mechanical advantage, but it also increases the rod tip speed. A stiffer longer rod will increase it's affect further.
Try a stronger tippet or increase tippet length.
"Raise the rod" don't set the hook if your fishing dries.
If using a tapered leader go to a longer leader. This provides more stretch.
Loosen your drag and apply drag, as needed, with your fingers or palm.
A stiffer rod will make casting and mending easier but no Bubba hook sets when fly fishing.
Keep the rod tip low to the water until the take, then quickly lift the rod with your wrist until the line is tight.
Light tippet demands quick delicate response. The fish and water conditions dictate how light you must go.

Good luck,
Gene

Hello Jason -- Here is a link to a MHX - 10' - 5 wt fly blank --- [www.mudhole.com] -- and also a 10' - 4 wt - [www.mudhole.com] -- Thank You

Bob McKamey
Mud Hole Custom Tackle
bobm@mudhole.com

Bob McKamey Wrote:
-------------------------------------------------------
> Hello Jason -- Here is a link to a MHX - 10' - 5
> wt fly blank ---
> [www.mudhole.com]
> d-Blank-F105-4-MHX -- and also a 10' - 4 wt -
> [www.mudhole.com]
> -Blank-F104-4-MHX -- Thank You

Mudhole MHx 10' 4wt ERN: 5.4, AA: 70, CCF: 75 as a 5wt.
This is my favorite stillwater rod.