gas mileage with a th350?
 

How much less gas mileage would I get if I tossed in a th350? I've got a 350tpi with 2.77 gears. What would I have to do to change it from a 700r4 to a th350?

you will lose a little off-the-line performance as well becuase the 350 doesn't have the huge 1st gear that the 700 does. If you want to know the mileage difference, just drive around with your 700 in D (no OD on 350's) and find out. You will need a vacuum modulator for your 350 and somewhere to hook it up. I belive (though I'm not sure) that if you use a long tailshaft TH350 you can re-use your original driveshaft??