A833 1-2 Clutch Sleeve Gear Binding

Is it possible to have too much endplay on the 1st speed gear?
Not unless you put the wrong bearing on the back.
A833s usually have a trans specific bearing back there which is wider than the stuff you buy at the bearing places. It used to be that you could only buy it at the dealer. I bought one of those a few years ago as a special order from a bearing specific jobber. It came from Japan, took a really long time, and cost me nearly $200Can. Ouch!
However;
in your case,
My guess is that your back bearing may not be properly located by the big snapring in the tailhousing.

BTW
My A833 trans has 1964 gears in it, but uses a Passon aluminum case, and a GearVender long-tail adapter on the back, a late 727-sized M/S, a Passon late-style cover, and with mongrel synchronizers modified for street slick-shifting.
Jus saying.