If you mean by 3/4 the length that goes only to the beltline then that's mine. Not sure the name of it but Olympia stopped making it in '09. I'm 6'3' to 6'4" with 36 sleeve. Mines is a XXXL and fits OK. I can't see how a XL will fit you. Mine is a little bulky but gets the job done. Length is OK.
3/4 is the jacket style that extends down and covers the butt, not the one that goes to the belt line. (called waist length, I believe).
My issue is the chest/waist measurement. I've checked it a few times and try as I might, I'm only getting 41-42" around the chest with a t-shirt on. 36" waist. My 42L suit jackets fit very well, but there was a time when I was lifting weights heavily that I went up to a 44L because the 42L was tight across the back of the shoulders. I tried one of those jackets on yesterday and I looked like a little kid playing dress up in his dad's clothes.
I was all convinced I would be well fit in a large Olympia jacket, based on the Revzilla videos and the size charts, especially with all the talk about the roomy, boxy cut, until I tried on a co-worker's Airglide jacket yesterday in size large (I think it's an Airglide, it's a couple years old, may be a previous model, but it looks like an Airglide or Renegade). With no liners, it fit through the chest/shoulders/mid-section more like a leather sport bike jacket, very tailored fit, but the sleeves were inches too short in the riding position. It could also have used a little extra length in the torso. The velcro cinch straps at the belt line were let all the way out. I was surprised, and I wondered if maybe they had changed the fit on the newer models, or if the 3/4 length "adventure style" jackets like the Dakar or Ranger might be cut differently. Hence my further indecision.
Sounds like an XL might be do-able in the chest/shoulders, but I find it hard to believe the arms are going to be that much longer over the large.
Firstgear Large-Tall is looking like the way to go, but I may go ahead and order the XL Olympia just to prove to myself it won't fit. Or maybe a dealer in Chattanooga or Nashville has one I can ride up and try on this weekend.