rear brake swap question
You may also need to look into whether the 11 x 2 brakes you have will suit the modified SBP axles that you currently have. With stock A body SBP axles, the distance bewteen the axle bearing and axle flange is less than large bolt pattern axles - by a total of 3/4 inch overall or 3/8 each side. Assuming your 11 x 2 brakes would have come a LBP car, this length variation may effect the mounting/working relationship between backing plate and drums (ie. when mounted on your SBP axles the drums may hit or rub the backing plates because they would be moved closer in towards the drum by that 3/8 inch).
As for your general question, I've nearly completed a big brake set-up for my 8 3/4. I bought some Raybestos 11 x 2.5 drums from Rockauto (about $43 USD each). I already had the correct backing plates though u see them on ebay regularly.
You may also need to look into whether the 11 x 2 brakes you have will suit the modified SBP axles that you currently have. With stock A body SBP axles, the distance bewteen the axle bearing and axle flange is less than large bolt pattern axles - by a total of 3/4 inch overall or 3/8 each side. Assuming your 11 x 2 brakes would have come a LBP car, this length variation may effect the mounting/working relationship between backing plate and drums (ie. when mounted on your SBP axles the drums may hit or rub the backing plates because they would be moved closer in towards the drum by that 3/8 inch).
As for your general question, I've nearly completed a big brake set-up for my 8 3/4. I bought some Raybestos 11 x 2.5 drums from Rockauto (about $43 USD each). I already had the correct backing plates though u see them on ebay regularly.