3:55 gears on the street

I don't know what that could be. I do fluid and filter changes regularly, and just drive them. I do like 10 over on the highway but a steady load should be the easiest on something like a trans.
Admittedly most vehicles I've had couldn't turn a tire if they wanted to, so I don't really try. I can't remember the last neutral drop I've done, or anything like that, never been on any sort of race track, I just drive em. They just don't last for me.
I have a 904 in a 78 fury, and so far it seems to be doing alright though I don't drive that one more than a couple thousand miles a year.
It does seem like it's getting tired, like piston
seals deteriorating,and I will probably just freshen that one up but even back in the 80s when late b"s were so much more plentiful I went thru 904 after 904. Then got married, had a kid and a couple of diplomats, and went thru a couple of 904s in each... Even in the "wife's car". They're junk. Put a 727 in and no more dead tranny. The one vehicle I had with a 904 that surprisingly held up well was in my 87 B250 van.