Ford Mustang Forum banner

What stall speed for fox body with AOD trans?

2331 Views 5 Replies 5 Participants Last post by  Cobrajet67
I am sure this has been batted around before but automatic transmissions are something I have always avoided. :sleep:

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
1 - 1 of 6 Posts
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.
See less See more
1 - 1 of 6 Posts