So lately I have got ls swap fever! I am slowly learning about everything that is ls since I'm a die had ford guy. I want to do a 5.3 turbo swap into a fox.

Now my question is what transmission to go with???? I want to go auto so that the car can run a good number at the track but I also want to be able to dd the car and get on the freeway. Now I keep seeing these people post that they are getting 25+mpg with a th400 setup...how true is this? What kind of mph can you cruise at with no overdrive and what rear gear and stall are you all running with those setups?

 

It's very true. My gto gets 31mpg on the highway with a t56 and 3.46 gears and that's weighing almost 4000 pounds.*With a th400 with a tight converter and 3.08's it would get mid 20's. As long as you spend the cash for a good, tight converter you're mileage will be fine.

 

4L80E..........A T400 w/od.

 

My car has a 400 with 3.08's and I was getting somewhere around 25mpg imperial at 65mph or so. I could have gotten much better mileage if I would have tuned for it. I am now running E85 and I haven't driven it enough to get a mileage reading with it. I cruise around 24-2500rpm at 65ish.