A Aod?

An AOD?

After putting some miles on my car I have come to the conclusion that an overdrive transmission is a good thing to get. At highway speeds I am turning just over 3K rpms with my current C4 and the 3.55 rear. The cost of fuel is just part of the issue, I would like to reduce the wear and tear on my engine by reducing the rpms when cruising.

For a long time I was sold on using a Gearvendor overdrive unit. I added up the costs of using a performance built AOD and the other needed parts and discovered there might be some savings using the AOD instead.

I would rather purchase a transmission built to take the power of my stroker than try and use or upgrade a salvaged unit. I have looked at what Lentech, Dr. Evil, and Perfomance Automotive and Transmission Center offer. I have a few questions to ask,

1) What other companies make a durable, high quality AOD?

2) Lockup or no lockup and why?

3) Has anybody used the wide ratio gearset available?

4) Can I get measurement from somebody of the width of the AOD pan and its distance from the subframe where the transmission cross-member bolts? I have TriY headers and a Magnaflow X pipe system in place and want to make sure there is enough room.

5) Converter Stall speed. It seems that 2K is the default recommendation. I have a fairly mild cam XE266HR in the engine, would there be any benefit or penalty if I used a 2500 rpm stall converter?

I am very intrigued with this fuel injection kit,

http://www.mass-floefi.com/index.html

it is something I am considering adding in the future. It seems like it would be a good match to the AOD. I just have to do better at putting away some extra cash in order to swing that purchase.

Thanks in advance for you help with this, Jeff

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http://www.cardomain.com/id/66hertzclone
 
66HertzClone said:
I would rather purchase a transmission built to take the power of my stroker than try and use or upgrade a salvaged unit. I have looked at what Lentech, Dr. Evil, and Perfomance Automotive and Transmission Center offer. I have a few questions to ask,

1) What other companies make a durable, high quality AOD?
there might be a few others, including art carr(i forget the name of his new company), but i recomend the lentech built tranny as they modify the shift pattern to a proper 1-2-3/od and you can get an od lockout as well.


66HertzClone said:
2) Lockup or no lockup and why?
since this appears to be a street driven vehicle, i say lockup converter. you will get better mileage on the freeway with it.

66HertzClone said:
3) Has anybody used the wide ratio gearset available?
in your case i would not use teh wide ratio gear set. you dont need it. if this were say a 65 galaxie that you were building, then yes use the wide ratio gear set as that is a heavy car that needs the extra torque multiplication to get ff the line properly.

66HertzClone said:
5) Converter Stall speed. It seems that 2K is the default recommendation. I have a fairly mild cam XE266HR in the engine, would there be any benefit or penalty if I used a 2500 rpm stall converter?
you would have a slight loss of fuel economy, perhaps 1-2mpg at most, and you would lose a bit of engine braking. otherwise the difference is very slight indeed. in fact you may not notice any difference at all, so either converter would be fine, as long as you can maintain the lockup function.

66HertzClone said:
I am very intrigued with this fuel injection kit,

http://www.mass-floefi.com/index.html

it is something I am considering adding in the future. It seems like it would be a good match to the AOD. I just have to do better at putting away some extra cash in order to swing that purchase.
yes that is a good system to run, as most are these days. and yes it would be a good match for the AOD.
 
1.) Hard to argue against a Lentech other than the price, but you can get a much cheaper B&M or TCI and have a longer warranty if that sounds like a good thing to you.

2.) Nothing to get too concerned about but here it is in a nutshell (and oversimplified)...a lockup will get slightly better mileage and run cooler, a non-lockup provides more power multilication and as long as the flash-stall is not too high (under 3,200) wont really hurt the temps or mileage much.

3.) Not me, the AOD is much wider than the C4 it replaced so i didn't consider it.

4.) No measurements handy but here's a picture of mine with headers on a vert. I'd say the X-pipe might be a problem, but I've decided I'm going to need some custom exhaust plumbing anyway since the vert is so confined underneath. The collectors on mine are behind the fat part so it might not be an issue at all.

randpsmall1.webp


5.) What stall to use depends on the power curve of the engine and how you intend to drive it. Opinions vary WILDLY on this topic so take them all with a grain of salt. Drag racing guys will say 3,800 to 4,500 and street-only guys usually stay around 2,400 or lower. it's worth mentioning that a given converter will stall differently in different cars, depening on the output of the engine. If you plan on a higher performance engine later (the FI you mentioned) I'd get around a 2,800, it might stall earlier in a low-performance application. In fact I did put a 2,800 into mine, and my car will see the drag strip only once or twice a year. I decided on 2,800 because I hit the 400 ft/lbs (flywheel) mark at about 2,500RPM.
 

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i run a 347 with long tubes and an x pipe and a 2500 stall non-lockup.

on the freeway with 4.10 gears i'm running 65 at 2500rpms. the lock up stall would of help to lower the rpm slightly and give better gas milage. they do make custom headers but are pretty expensive or you could try to bend the TRI Y's out (someone on the forum did this).it a better fuel economy but i race the car more then use it as a daily driver.

you will not be able to use your headers due to the width of the AOD. i'm using summit racing headers for the 351W which work fine but hang a little a low to the ground. the 302 with the shorter deck hieght and not being as wide as the 351w any headers for the 302 will not fit. i also had to make a 1" engine block (motor mount) spacer so it would raise the engine to compensate for the wider headers otherwise they do rub on steering box.