Chris3 and I have been discussing preping a new trans for next year in the offseason for the Duster, any recommendations for "must haves" ie, bolt in sprags, alum drums ??? 727 vs 904 ( have been told that a 904 behind my small block will be .5 sec quicker Just looking for ideas and suggestions before we get ready to start looking @ parts and prices

More info please
What engine / power output?
What stall / gearing / tire size?
What is the cars weight?
Is this racing only or street/strip?
Are you using a trans brake?
What is the budget for parts?

FWIW, this is what I am currently doing for my Charger:
Engine is 500" stroked B and should make close to 700 HP. This is a street/strip car weighing #4,150, with a 10" converter rated for around 3500-4000 stall and I'm running 3.91:1 gears with short 27" tires. No trans brake (I run a "street" class that does not allow trans brakes, slicks, or open exhaust.)
Anyhow, I'm using a 727 with the TCS steel drum.
I think all the aftermarket drums use the wide drum bushing, so I needed to swap my '70 (and earlier) pump stator support for a '71 and up style. The support has been modified, and the case and pump have been drilled and tapped for a rear vent and possable future trans brake use.
The pump is getting the max lug gears.
As mentioned earlier, a billit steel drum (for saftey and street use), a lightened sun shell, the billit steel 4-pinion front gear with roller thrust washer (from Cope racing), Alto red clutches, kolene steels, aftermarket servos and accumulator, heavy duty band strut, 4.2:1 lever, a high performance flex band, A&A ultimate sprag, aluminum rear clutch retainer (it has the correct bevel cut to clear the new front drum), and a few other odds and ends like bushings, and such. Currently I am just going to run the stock valve body modified with the trans-go TF2 kit, but as mentioned earlier I am doing the mods needed if I decide to install a trans brake later. I did not go with the full roller/roller support setup to help keep cost down, and the roller support setup eliminates the govenor, so you have to run a manual valve body.
I also had to cut the front tabs off the case to fit the CSI trans shield. I am also using the Lokar cable kickdown setup, so I should not have an issue with the kickdown interfering with the shield.
I also had to get the dipstick tube that clears the trans shield, and a heli-coil kit to fix a few stripped pan bolt holes.

What is your budget ? Is this a max ET effort car ...or something that you are going to run 500 passes a year ?

The absolute MINIMUM I would do is an aftermarket alum or steel front drum. A heavy car - steel. Lighter ? .. alum.

IF you have a uNlimited budget .. you can throw the kitchen-sink at it ... and buy everything. Rollerized, straight-cut, low gear, etc - ETC.

But that bolt-in-sprag ...... unless your case has had a spun-sprag in it ... is throwing money away.