Ordered new brake shoes from the auto parts store... they came in so i got the old ones off to compare to the new ones wich are 10x2" well the old ones are exact except......there 10x1 3/4"......... will the new pads work??

no

You got to be kidding me...

What will be the differance the drums on back dont seem to look any differance the ones off the cuda??
the rearend was narrowed long ago but was under a dart..

I never kid around on Moparts . Maybe I missed something but the new shoes would need to be the same width as the worn out ones that are being replaced. 1&3/4 to 1&3/4. 2" to 2" & that does sound too simple, maybe I did miss something. EDIT which rearend & sbp or bbp? MORE EDIT SBP 8&3/4 (1&3/4 shoes) uses a specific rear backing plate/drum. The BBP rear brakes use a different backing plate/drum & the shoes are wider than 1&3/4 (2" maybe) & aside from the different drum bolt pattern there's no interchange because the axle standout is different between sbp/bbp

If the brake shoes are the same and the pad is just 1/4 narrower; don't see why it wouldn't work. Would probably improve the front / back bias too.

I asked Ebooger about swapping in 11 x 2 instead of my 11 x 2.5 and he couldn't see any reason not to do it.

Yes, I've already changed the WS, and don't want to add an adjustable valve.

The bolt pattern is the big pattern the old shoes are 10x 1 3/4" i called auto store they said they could get a 10x 1.75 and a 10x2.0 so il have to wait till sat when they get here

I think the answer Robert gave you is right based on the information provided. Every shoe has its own backing plate or 'frame'. Yes a person can swap some around, but the risk is on you. Even 10 x 1.75" shoes are not all interchangable - the holes for the various springs, hold downs, etc are not quite the same between a 171 (Ford), 256 (Mopar -'67), 288 (mopar '67-8) and 331 (mopar '69+).

So things that can go wrong with the wrong shoe include problems with self adjusters working, hardware binding or scraping, and with an undersize lining, reduction in rear braking with increased heat.
Also as drum brakes are self assisting, and when things are physically off just a little bit they can quickly lock up. On the other side, when the lining is overheated it the self actuating goes away as well. This means a lot more force has to put on the pedal. This is not likely to occur around town. It takes a good stop from over 60 mph or decent down a mountain to get that much heat generated.

Anyway, take a look at the old shes for a number stamped on the metal frame. Thats the FMS number for the frame or shoe number regardless of who manufactures it. If its any of thes above numbers, then it too is a 10 x 1.75" shoe. If its 333, then its not.

Also, if you look on the edge of the lining itself (or sometimes an ink stamp on the backing plate) there are more numbers. Thats the friction lining information including who made it and the friction rating under test conditions per SAE J866. They are a very rough guide to help techs replace the linings with a similar performing product. So if your old lining is marked FF, and the new ones are EE, then the new ones have less friction both cold and warmed up.

Before i take the new brake shoes back ...from these pics..is it possible that a prev.owner put wrong size pads on reason i ask is looking at the drum where contact area is and being a 1/4"differance in width between the old/new pads (everything else is the exact same but width)
Looks like should of been a wider pad??

...

Better pic of what i was talking about

I'd suggest going with the original size 1&3/4 shoes. K.I.S.S. You know they will fit, the 2 inchers may or may not fit (I would think no) & if they did you'd want to turn the drums. Less rear brake bias (which the 1&3/4 VS the 2" would give you) is almost always a good thing so I'd highly suggest staying with what is on there

Ok then back the new ones go thanks

Not to hijack the thread but now I have some questions as I had this problem last week while a buddy and I were putting a new 8 3/4 BBP rear in my 69 Valiant. I had some 10x2 brakes in the garage and needed some backing plates. I found a set of 10" on the shelf and was happy I found them all. Went to put them together and the stuff wouldn't line up. As Robert stated I think the backing plates were from a SBP A body 8 3/4 that were 1.75 and not 2". So what I did was got all the stuff to match backing plates and put a 2" drum on them. They seemed to line up OK but did notice the drums rubbed on the backing plate a little. I understand you don't approve of the difference in shoe widths but what is the correct solution for that as I don't know if they make 10x1.75" drums in BBP. Or another question would be when changing axles in a A body 8 3/4 what brakes should be used? IE the entire set from some BBP car?