I just recently replaced my 260 style balance tube on my 73 240z with an orignal style 240 balance tube that didn't have the water lines and egr and emission stuff. The problem is that now since I have replaced the crank pulley and the balance tube, I used about half a tank driving about 40 miles. I used to average about 185 miles on one tank (even though that is not really good either). The car has upgraded to ZT S.U. carbs. So my question is why has my gas mileage gone down so much. Do I need to reset the timing, blance the carbs.. or should I go back to the other balance tube?? Please help.

-thanks

i get about the same mileage on stop and go driving. Freeway driving i get slightly better mileage, but i believe i could definitely do better. Perhaps my heavy foot has a small part in my mileage as well...:sleepy: