Transmission is out - need some ID help

I got the transmission out this evening. That was definitely not fun. Even with taking out the cross member, it was still a . I must say that I was past my level of knowledge and experience doing it.Here are a couple pics of the numbers.

http://www.VetteRegistry.net/member_uploads/4601_4700/4691/trans_tail _number.JPG 

http://www.VetteRegistry.net/member_uploads/4601_4700/4691/trans_vin. JPG 

 

And here is my VIN:

194671S102694

 

Am I correct in reading that this is the transmission that came with the car? I read the numbers as a Muncie, made in 1971, August 27. Is it an M20 or M21?

 

Thanks in advance to all the number reading gurus!

You are correct in assessing it is the orig. unit for your car. Excellent!! The vin matches.
The "P" is for Muncie
the "1" is for the '71 model year, not the year of manufacture.(this trans was built in Aug., of 1970)
M = August
27 = day
There should be more nums there, tho, that would give the ratio. After the "7" in 27, I can barely see them(it). Maybe if you take a close look you can make them out.
Should be a B, A, C, or P.

The last letter is an A. It's barely visible - very faint.

"A" = M20 Wide ratio 2.52 first gear(low)

Thanks a bunch Joel!

So it looks like my car is original. I guess the orginal owner who did the old frame off cut out the welded in cross member and put a bolt-on in. I can live with that mod . Now I guess I DO have to get the original engine down here .

John, it would be very obvious if the crossmember had been cut out. Here's an idea...
At the driver's side rear of the frame is the vin #. It is stamped on the top of the frame, to the rear of the tire area, by the rear body mount. They can be really hard to see, but with some cleaning/scraping, and a mirror, you should be able to see it. If that number matches your vin, then it is the orig. frame, also...just "bubba-ized"!