Smoke and Leaking Transmission Fluid

Last night in Cedar Rapids we had a "Cruise The Avenue" parade and hundreds of classic cars came to drive up and down the avenue along with the general public. After one pass the traffic was bumper to bumper and moving at a snails pace. I was driving my 67 290 automatic Rogue and all went well until I noticed my temp gauge rise up to the middle of the gauge. It normally runs around the 1/4 mark. I put the transmission in neutral and would rev it a little to move some air flow through the radiator to prevent overheating. I decided to turn off the avenue onto the interstate after about 30 minutes of crawling along behind tail lights as far as you could see. My son was following behind on his motorcycle and noticed a lot of smoke coming out from under the car when I accelerated. I assumed it was moisture or unburnt fuel from idling so long. Bottom line I drove about 5 minutes home at 45mph. I parked outside the garage and let things cool down before pulling into the garage. when I moved the car into the garage there was a puddle about 4x8 inches on the driveway. Red transmission fluid for sure. I put cardboard under the car to catch additional leaks and noticed the exhaust pipes had burnt red streaks on it along with fluid on the underside of the car. I haven't had a chance to raise the car up to see where its coming from, just curious what others think may have happened and what seals may need to be replaced or what to look for. Is it possible the transmission fluid overheated and the fluid leaked out the fill tube or did I lose a seal somewhere? The car ran fine and I didn't notice any shifting issue. I need to go to my other garage to grab a floor jack and jack stands so I can crawl under the car to do further investigation. As far as leaks in the past, only minor, as with all old cars there is minimal seepage from transmission pan, engine oil and occasional antifreeze drips under the car. Nothing like this! BTW I just pulled the Rogue out of storage for the first and hopefully not the last drive of the season.

The transmission is the aluminum M40 I believe.

I had a '68 Javelin 232 automatic that overheated and boiled out of the dipstick tube, this was after doing a lot of slow hill climbing while looking for an address.  There weren't any seal leaks in my case.

Fred_Frick wrote: Or how about a leak from the trans cooler lines.dripping or spraying on the hot exhaust.

Ah, another issue... since it was a new replacement... lines may not be tight at the cooler.

Also I get confused, on what year is air cooled... then no lines?

Update on the smoke and transmission leak.