Oh yes, absolutely! Stock for stock, the Bavaria is a joke compared to a stock M6, but I thought it was pretty clear that wasn't my point since my car was heavily modified. I built what BMW built with the M5 many years later...a very quick, 4 door sedan with decent room and trunk space that handled very well. I went a bit further with the suspension though.
The stock Bav had a 19mm front sway bar...mine had a 28mm bar with plastic bushings and Korman's mount reinforcements (and considering the stiffness of a torsion spring varies with the 4th power of the diameter...lol), etc.
There's NO contest between a stock Bav or any car of that day with a stock E24 M6...just like there is NO contest with your M6 and my E39 M5 or your Z8.
Regarding weight...it's actually more than 400 lbs lighter I guess now that you show the M6 weight. The spec weight for the 72 Bav was right at 1400kg which is just a bit less than 3100 lbs. The later E3 cars (1974 onward) had the big bumpers and other luxury stuff, and they weighed in around 3400 lbs. The 72 Bav though had no electric windows/locks/etc, no big bumpers and their chassis reinforcements, etc...
I'm not attempting to make any claim that the Bav was a better car...just that it was a lot of fun to play with the M's when they came out and have them walking up and asking me about the Bav after a track session was over. The Bav became well known in the CCA National Capital Chapter for being a track monster and also always winning FTD at the autocrosses. It was much harder to properly setup and modify a car back in those days than it is now. I was fortunate to meet Ray Korman at the right time.
Speaking of Ray and mods...many years back now, I can remember when he built his first "major" M6 with 45mm Webers, head porting, hot cams, special headers, titantium rods, the whole works. What a monster that thing was, and it sounded about as sweet as any 6 cylinder BMW I've ever heard.
Also, the craziest thing just happened last night. I get an e-mail whose subject line is the VIN of my old Bavaria (I sold it in 1994 after 22 years in the family) along with a picture of the VIN tag. The e-mail said "I would like to speak with you" and had a phone number. I called the number and talked with the current owner who just bought the car. Unfortunately, it had been left sitting outside by the guy I sold it to for years and is in rougher shape (it was always garaged for 22 years). Oh well...
It's too bad you're on the west coast as I would love to see an M6 with 33k miles by the original owner.
P.S. If you turn the clock back to 1971, I think most will admit that the Max Hoffman put together a great combination with the big engine and low optioned car to create the Bavaria. It was a sign of things to come, and that simple combination he spec'd out for BMW AG helped them really understand the US market. This was the beginning of the true 4-door performance sedan market.