If installing a manual in it is plausible I would go that route. Reliability would go through the roof and so would the fun factor while driving it. Install a set of 4.10 gears in it and you will be very happy.
Shop still has my Mustang to this day. He rebuilt the trans again, says it runs good and shift good, but the converter won't lock up. He's currently replacing all the items that control that function one by one. If it doesn't fix it, he returns it. Says it may come down the the computer being replaced.
I know it. Rick is a friend of mine, so I leave him alone on it. It'll be done when he says it's done. The water pump is dripping slightly. I told him, "go ahead and swap out the water pump if you desire, so there's some money in it for you and your son. If the computer needs to be changed, it's on me."
Maybe my original pedal position sensor was bad and I never knew it? Went out cruising late last night, nice cool temperatures. At one Stop light, I hammered it on the green. Both back tires started spinning. When it made the first-to-second shift, got a real beautiful chirp. This, from a 4.0 V-6 auto? LMAO!!
My tires are 255/35-20 Nittos.
Rick does his own custom shift kits. The car has one now. Shifts are hard and firm. I like it. Thinking about replacing the 3.73 rear end gears with 4.10. Did that on my V-6 Ranger. Wow! What a difference!
I have 4.10s in my 2007 GT and they are great. I do a lot less shifting when driving around town. I can lug the engine down to 1,200 RPM in fourth and accelerate lightly without a hiccup. A good thing to do along with the gears is to get a canned tune. This will let you get the speedometer right while making some more power. SCT has a nice Bluetooth OBD2 dongle for $269 that uses an app on your smartphone to interface with the vehicle. You get three tunes with it for three octane fuel levels. This way you can run 87 octane when you don't need/want the extra performance. You will probably pick up around 20 RWHP using the 93 octane tune.
I don't know how the speedometer reads in a Mustang. In my Ranger, it works off a tone ring on the ring gear in the differential. Changing the gears didn't affect the speedometer at all. Only tire diameter affects it. Both my Mustang and Ranger have a 7.5 diff. So maybe it's the same.
On my 2007 GT the axle ratio is set in the tuning software. If I run the stock tune with the stock ratio it jacks up the indicated speed to the moon. I can also fine tune the speedometer by slightly tweaking the tire revoutions per mile setting. The axle ratio change gets it close but the tires on mine aren't stock size so I have to adjust the tire revolutions per mile number too.
No, still have the automatic transmission. It's been fine ever since the last rebuild. No problems whatsoever. All the problems I was having with codes for misfires went away after the installation of a new throttle body and new foot pedal assembly. Cars doing great!