In '71 they went with a sort of "one size fits all" disc brake master cylinder p/n 3461176 (B, C,E, and some light trucks). A bodies used an almost identical master cylinder (casting number and bore diameter same). The only exception I know of is the p/n 2944476 which was carried over from '70 for disc brake hemi cars.
The 2229171 casting number is the p/n 2944453 which is '70 e body disc brakes only. You can look on the fender side of the casting of your '9171 for a date code, the upper line will include "9175" which is some sort of assembly line or plant code, and the line below it will be the date code. "9 324" for example would be the 324th day of '69. Anyway, check that number and see if it seems at all close to late summer/early fall of '70 to get an idea of if there is any hint that one could be the original for your car. I've never seen a '171 on a '71 E body, so I doubt any were built with them.
But as they say with Mopars, anything was possible I guess!

I love it.I want to do this with everything I own.My 'Cuda.My Charger.My S10! and cars I don't even own yet!

My casting is too rough or rusted to get any kind of numbers off of it.

keep 'em coming Alan. I can only hope mine comes out 1/2 as nice as yours !

on my 71 gtx oct 10 1970 disc brake master cylinder is casting number is 346187

Ok...So Brewers came through with the correct flywheel in record time and UPS was kind enough to only add on another $85 to the cost

But here it goes...The engine transmission were mated

...everything seems to be ok....

Here's the wind-up...a straight drive right up the center

....and PRESTO

Total time including assembling trans-motor was under 4 hours

...have wheels....lets roll...

Underside....

You are quite a barrelcuda pimp

but that looks very well done

like watching a new car get built.

Nice job man, those pics put a smile on my face! Can't wait to see it all together.

Looking good Alan, I can't believe that is the same car. Are you going to take it up to Marrit Hall Ancaster this weekend and show it off ? Dave.

Wow---i really cannot believe how awesome of a job you are doing! Its just amazing, simply amazing Allan! Would you like to do my Charger for me!?

Alan, why didn't you paint the bellhousing?