as title says. this is in my 85 D150 w/a slant. original to the truck was (surprisingly for the mid-80s) is a lockup 727. Shifts awesome, except lockup doesn't.... (I know its a lockup version because I ran the "PK" number which says it is) I was surprised to see the 727 in there. Yes I can tell the difference, not one of those guys that think "every" Mopar trans is a 727, haha) I have been working on a "beefed up" slant, to replace the weak kneed original as funds have allowed. I'm not yet driving this truck though "I could," as is. Just tired/doggy. Starts easy, runs like a sewing machine. I have never had very good "luck" with 904s. I have swapped 727s in place of 904s in many of my past vehicles. even in otherwise "stone stock" vehicles. after the 904 grenades. Yet, I have had several tell me to downgrade to a 904, even though it is in a truck. I have so far resisted. May need to swap converters anyway because I'm expecting to see ring gear tooth damage once I get the engine out (you should hear the starter working, you'd say the same thing) Thing is I have had a /6,904 fall into my lap recently without looking for one. I've never before downgraded to a 904 from a 727. This 904 was said to be a "good core", I know its converter should be changed too, snout on it is all rusty from sitting under a lean-to, for IDK how long. I know how to overhaul them, I've done more than a few. And would, as a matter of maintenance, (especially with its unknown history) before I use it. (though when I got fluid all over me when I put it onto my trailer, fluid didn't seem burnt) This 904 is non lockup, splines go all the way to end of input shaft. I haven't run the PK number yet to see what its original application was. Might this 904 have the lower 1st, even though its non L/U? what converter options are out there, other than exact same stock replacement for a 727 L/U? If Im gonna have to replace the converter, Id like a little "stall" (not crazy) and to see if I could maybe get a 10" version, I believe the one in it now is 11". Was there a factory "lo stall" and "hi stall" for the L/U 727 or were they all the same in those years? If there were a "lo" and a "hi" from the factory for a L/U 727, how low was the "lo stall" and how high was the "hi stall" version? which trans would you run if this was yours? truck is 2wd, long bed, 3.21 geared. truck destined for 3 season daily driver, occasionally (2-3x a year) will be used to pull a light (~2000 lb total with my "gear") pop up on mostly flat, Midwest roads. I know I might gain some "get up and go" off the line with the 904, but what would I lose in durability? This is NOT a "race" truck! How much more available engine "power" is eaten up by a 727 vs a 904?