34B if you have 2 vents. But the last time I installed one you had to get a 34B and transplant your old 70 filler neck. Since then some like the Spectra sold by Rock, have a filler neck already installed. The neck fit remains a potential source of trouble. The troubles range from being too long, not being clocked correctly so as to allow the gas door to shut all the way and the filler neck not being at the correct angle for the filler neck door opening. So keep your old neck. Caveat: 70 California Larks may have a dedicated tank. My comments above relate to the other 49 states.
Jim, I'm posting this for a friend. The tank the repair shop picked up for him has the neck issues. Too long. Any out there correct??
The longer ones are for 71-2 tanks. Necks are just soldered onto the tank. Make sure it cannot be clocked into the better position relative to the door. I am not current enough on what is out there in the reproduction world except for used 70 factory necks. Used ones can be made to look new.
