i got 91 that has sorry brakes will this work

I cant see any reason why not. Its a Dana 70 or 80 isnt it?

Its a good idea to get some speed bleeders - makes flushing the system much easier.

Russell Performance - Domestic Speed Bleeders

A word of caution though - if you have replacement calipers you have to make sure you measure the proper size of bleeder. The bleeders listed on the site are for the OEM equipment.

Rear Drums, Dana 70
 

Related, but slightly off topic. My '01 has a Dana 70 rear end. The previous (orignal) owner said he had to pull the axles to get the drums off. My ancient (1965) Dodge truck was setup this way, but my '99 isn't. Is he mistaken?

To get the drums off? I think hes mistaken. Look at the pic above - the drum is off and the axle is still in place. The "drum" is the outer housing that the shoe presses against to stop the truck.

I was hoping that was the case. On the older 3/4 and 1 ton rear ends, the drum and bearing hub was one piece. That never made any sense to me, but that's the way they were. I believe the '01 Dana 70 drums are just stuck to the hub pretty hard. The bearing hub and drum don't appear to be one piece. Early in this thread (or the other wheel cylinder change thread) The OP talked about breaking them loose by pulling the wheels with sturdy jackstands under the axle, starting the truck and putting into reverse, giving it some go-pedal then stomping the brakes. I'll find out soon enough.
Thanks,
'Dead Stick'

That trick works very well,,,,but keep at least 1 lug nut on or you will be chasing your drums down the street.

I wouldn't even give it no gas, idle speed does the trick just fine. Don't get to crazy on this, don't want bad things to happen here.

Depends on how much rust you have - I had to giver a little go pedal.

When they're fresh I never even put it in gear, just start the truck, give a push on the pedal and off they flop. It's almost sweet how simple it makes em.

Then on the other hand I've had em in such bad shape that they didn't even push hard enough to put pressure on the drums. Out comes the BFH.