Build AOD vs. Build C4

[roush08]

I currently have an 87 5.0 with pretty stock motor, full exhaust, Mickey Thompson street drag radials and 4.10 rear end. I am interested in opinions on building the stock AOD - what parts are recommended vs. dropping in a C4. I realize the C4 is known to be much stronger and built to handle the stresses of weekend racing and spirited driving, but with the 4.10 gears I'm afraid of loosing overdrive. Has anyone switched to a C4 from an AOD and regretted it and why ? Can an AOD be built to handle the stress of a weekend racer and if so - with what parts ? There are plans within the year to build a motor with 350-375 hp and I was hoping to have a transmission in place to handle the power.

[silver03tt]

I have had two Performance Automatic super comp c4's over the years. Both cars had 4.10 gears and both transmissions worked great. With that said if I was building a transmission for just racing I would stick with the c4 but if I was driving on the street alot I would definitely run an aod. Driving 40 miles with a c4 and 4.10's can be pretty annoying considering the engine at highway speed is turning about 3500-3800 rpms. I know aod's can be built plenty strong. I think Lentech has a version that they claim to handle over 1000hp and PA has some that they claim for 700hp with warranties. Depending on how much street driving you will be doing will be the decision.

[biminiLX]

All-out builds and the AOD/4R70W can handle more power than a C4.
You will want an upgraded input shaft and either a Freddy Brown or Lentech valvebody for huge power.
PA and SilverFox transmissions can also build great units, but if you have 800+ hp I would only run Freddy Brown of Lentech.
I just went through this debate and went AOD.
Check out clickclickracing.com for good AOD/4R70W tech.
I also have a 1500hp rated Lentech Strip Terminator input shaft and machined drum if you go AOD that can save you some money.
-J

[roush08]

Any recommendations for someone to build an AOD ? I'm about 20 miles east of Pittsburgh and willing to travel if necessary. Just seems like whoever I start to talk about building an AOD to, their opinions are to go to C4.

[biminiLX]

If you are only building for 400hp or less, either will do just fine for little money.
Comes down to how much you want OD.
Plus you already have the AOD, so you're ahead there.
Street Lethal up near New Castle works with Abruzzi Transmissions in Ohio and they do excellent work.
Upgraded input shaft, a valvebody (do you want to shift it manually or keep it full auto?), and basic performance rebuild will take 400hp all day long.
-J

[Balaska347]

All very good info above. It depends how much you want the OD. On the street even just driving 40 miles to the track is worth it to me. For what you plan on doing like J said, a input shaft, manual valve body, and a performance rebuild kit will take 400rwhp all day long. I know because I have done it for 8 years with a thousand passes on it.

[Naste95]

This will give you some idea of what your engine will turn at certian speeds.

Here is a rpm/mph formula I found. MPH x REAR GREAR x 336 divided tire height Example 119x4.10x336/26=6305rpm cruising speed 65x3.73x336/26=3133rpm
This is for the drive where your tranny is 1:1