So for years my friend told me this horse was a certain breed, I do NOT see it. I need your eyes people, your beautiful equine-breed-defining pupils and corneas. What breed or breeds does this horse resemble strongest? List all the possibilities. He's passed away now but I'd love to do a memorial line in his honor one day. It would be super helpful if I got his breed right though...

  Oh, he was roughly 1250lbs and 16.3 hands

I know very little about horses but I get a Morgan x Quarter Horse kind of vibe.

He's stunning!! I also get a Morgan x Quarter Horse vibe as well. Not a 100% but he could also possibly have some arabian in him. 

First pic makes me think Arab. But I agree, I think mostly Quarter Horse x Morgan.

My first thought was a Morgan cross. He's got good size and some thick legs, so as far as the cross, I'm not sure lol. 
He was a lovely boy for sure

That was one straight profile!

As for breed, I have no clue.

Def looks like a Morgan cross to me!
Maybe Morgan/Quarter Horse cross or even Morgan/Missouri Fox Trotter cross???

That's what I noticed too Kuwait! I'm terrible at this but with the face and the height I want to think more warmblood-y but then those legs are thiccc

I was told he was a "Running Quarter Horse" which I suppose is the old term for Appendix Quarter Horse. IDK, he had a funky gait to him too when he trotted but it wasn't smooth it was like riding a jack hammer lol. At one point I felt like he may have been a cross with a heavy boned gaited breed lol.

We need to get Neke and Overture on here since they're the QH experts in real life! At the very least they can compare to what they're looking for in breeding stock.

he looks like a morgan x quarter horse to me

I would say that is, in fact, an Appendix QH.
(Running QH is just slang for Appendix, and Appendix is technically a QH that is generation 1 from a TB and QH, though it's often used for gen 2, 3, 4 etc. so it becomes a percentage game).

At 16.3HH and with the way the back, shoulder, and haunch is shaped, as well as the high set of the withers and the muscle structure, I would wager a higher percentage of running lines.  With the height of the bum looking higher than the front, it can throw off the gait in slower speeds (which is why they feel odd), but increased the sprint power from a dead stop.  Also good for jumping!  Also, the face is very similar to a load of Appendix horses I see day to day.  There might be more cross in there, but this guy looks a lot like three of ours who are Appendix.

Something to keep in mind with QH and TB (and therefore Appendixes) is that there is such a huge variety of sports that they are used for that two animals from the same breed can look entirely different.

My moms mare, Sassy, is bred for halter showing -  She has a beautiful face, slight dish, wide forehead, thick mane and tail, and the world's tiniest legs and feet.  Meanwhile, Jane, who is in the high 90s for Foundation (AKA the original QH) is stocky, taller, and has an ugly moose face ♥.  And Drift?  She's Appendix and while her conformation is quite good (because I am picky as heck), she is over 16 HH and leggy and at a glance, you might go "Thoroughbred", except she's not.  So all three mares are QH - yet if I bred all 3 to a TB stud, I would get 3 very different shaped foals, yet all 3 foals would STILL be Quarter Horses, registered, and called Appendix.  Quarter Horses, Appaloosas, Thoroughbreds, and Paints all have a lot of overlap, dual registration, etc.  So you can 100% have a horse that is both QH and a Paint, and a QH that has loads of TB. 

Side information:
While Morgans can be taller, they do average in the 14.2 to 15.2 HH range; unless they are from those breeders specifically trying for height, it would be rare for them to get that tall. Additionally, while they can have a straight face like this boy, it is typically shorter, and with larger eyes.  A broader face is more common, and very delicate looking. There's a lot of things that sort of look Morganish on this fella, but the height is a huge indicator.  Also the lack of Morgan ears, which are very distinct and predominant even in part-breds. And the feet.  Morgans are powerhouses and they often have very beautifully formed feet and this guy does not seem to.  Obviously not always true, but to me I see very little Morgan hints here.

Thank you Neke! That was a huge help :D And your explanation has helped me see it now!

♥
Anytime.

I am for sure not like, a Goddess of all things QH, but 30 years experience does help!

Neke, I wish I had just a FRACTION of your equine knowledge

Ris, he was absolutely stunning

@Vida; I am working on doing info sharing at the education station!