A week ago I took my finally-running '70 for a short drive. First to the gas station (~2 miles), then got on the highway, and exited at the first exit (~1.5 miles). I stopped at the light and when I turned, this huge cloud of smoke enveloped the car behind me. It was bad. There was also smoke coming from the edges of the hood. I pulled over and noticed a few drops of coolant coming out the overflow. Thinking I had overheated, I waited 30 minutes and drove slowly home (2-3 miles). The next day I noticed fluid under the car that was light red. Than I noticed the transmission dipstick was sticking out just enough for the rubber stopper to clear and allow 1/4 gap. Right in that area, everything had been sprayed with trans fluid. I was thinking I had left the dipstick undone and that the fluid spurted out (like the oil would), but now I understand it shouldn't spurt out even if the dipstick is ajar. So, I read some posts here and learned I may have (1) a clogged vent on top of the tranny case, (2) constricted/clogged cooling lines, or (3) some other problem. I've never worked on a transmission. Where is the vent and how do I clean it? Is there a good way to check/clear the cooling lines? What about the radiator portion of the cooling lines? Do I take off the lines and blow thru them all? Any other ideas on what could cause this? Thanks for any help/suggestions!