What stall speed for fox body with AOD trans?

If it's a car that's driven on the street(presumably) then a torque converter that isn't a really high RPM stall speed would be best. I think a stock AOD converter in a GT already has an almost 1400rpm stall(1300 something from what I remember). So probably about a 500rpm or so over stock which would be like an 1800-2000rpm converter would be good choice imo. You would benefit with even a mild converter for the street.
The mods you describe aren't going to have you need a really high stall converter. You're essentially planning on making a slightly hotter late model 5.0 Explorer engine since a late 1990s Explorer would have had many of the parts that you're describing already sans the cam of course. The E303 isn't a high RPM screamer cam where a higher stall converter might be beneficial for the track. It's a good low-mid RPM street cam that will give you good street manners, retain decent vacuum, and a reasonable idle.
For an AOD trans TCI makes the Saturday Night Special which is about 500rpm over stock and good for mild builds. It retains the lock up and this is what I had bought for my 1991 GT. Then they jump to the Streetfighter which is about 1500rpm over stock which is quite a bit for a street car imo. You have a lock up or non-lock up version with that choice.
There's plenty of other brands out there too that may give you an option in the middle closer to 2200rpm.
Take note that the higher the stall RPM the hotter the trans will run especially at lower speeds as you'll also have more slipping. A non-lock up converter will also generate more heat at higher speeds so I recommend a lock up.

If you are principally cruising, you don't need to change the stock unit. The purpose of stall converter is essentially to hide the fact that performance cams can suck in bottom end performance. The cam companies want you to put a higher stall converter to spin up engine higher before moving.

On a race engine on the track - sure, it lets you launch at your engine peak torque to get you moving as fast as possible. But for a street cruiser, not needed. I would recommend a good shift kit though.

My 90 GT has a similar engine set up as you are proposing - GT40 3 bars, Crower 15512 cam, 1.7RR, Explorer intakes, 70mm TB and EGR, 76mm MAF, 24 lbs injectors, shorty headers with full 2.5" exhaust - power estimate 320-350. My 150k AOD was totally stock except a Lentech Street Terminator valve body - my big fat 3800 lb car would trap a 1/4 mile on the street at 103 mph launching from idle. I would still have it in the car except I killed 3rd gear powershifting at 5500 rpm last year. I'll rebuild it someday with the guts from a 4R70W, but a T5 from a 94GT lives in the car now.

Good luck with the build and keep us in the loop with progress.

My 89 LX has a similar engine set up as you are proposing. GT40 upper and lower intake, FloTek aluminum heads, B cam, 4.10 gears. I went from the stock converter to an 1800 stall, 2.0's short time and 13.2 quarter mile times. Upgraded to a 2800 stall, and no change whatsoever. Spent more money and went with a 3800 stall, and the first time I launched the car at the strip it actually scared me. The launch felt so violent compared to what i was used to. My times dropped to a short time of 1.65 and quarter mile times are 12.50. The car is very streetable with no problems driving around town. My recommendation is don't waste your time and money, go big, or don't bother at all.

rudifisk said:

I am sure this has been batted around before but automatic transmissions are something I have always avoided.

Now I have a 1989 fox body with 5.0 and AOD trans. I am looking at doing some work on the car this winter and will be replacing the stock heads with the better flowing GT40P heads from a Ford Explorer as well as the better flowing intake manifold. Next a slightly larger throttle body, a better flowing fuel pump and regulator, larger injectors, and cold air. And shorty headers with new exhaust. And a new cam. And that is everything (ha!).

I will be rebuilding the AOD so while I am at it I am wondering, what stall speed should I anticipate needing for the torque converter? The cam will likely be an E303 or similar. I am hoping that some of you folks have gone down this road before and will offer advice based on my intended mods. Thanks for the help.

Randy in Everett, WA

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Usually the cam manufacturer will suggest a converter stall speed Trick Flow recommended a 2500-3000 rpm stall speed for my TFS Track Heat Stage 2 Roller Cam. I actually went with a Monster 2800-3200 rpm stall.

Jarhead1967 said:

Usually the cam manufacturer will suggest a converter stall speed Trick Flow recommended a 2500-3000 rpm stall speed for my TFS Track Heat Stage 2 Roller Cam. I actually went with a Monster 2800-3200 rpm stall.

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It'll really depend on the cam profile. If it's a higher RPM cam then a higher RPM stall converter would be helpful but only so much for street use. The OP's planned cam is a low to mid RPM cam which will be best for the street therefore a high stall converter will not be helpful to him.