There is an electronic and non electronic version of AOD

Shops build them for race engines taking alotta abuse.

http://www.becontrols.com/ourfaqs/aodfaq_1.htm

 

I'm sorry I cud not figure out how to post a PM, so I will do it here. pkupman you say that you have done the ZF swap, I also wud like to do this. I have both trucks5 F250 with the ZF 351W 2WD LWB. The truck I wud like to put the ZF in is a 91F150 300 Mazda tranny and Extended Cab. I already have the tranny out of the F150 due to bad slave cylinder. This is a no brainer swap you say, same clutch,flywheel, slave, driveline, etc. Please let me know. Sorry about going out of the way on theis thread.

 

Jimbo Beam:

Thanks for the tip regarding the Gear Vendors unit. I had no idea they were out there. This has sort of thrown a wrench into the workings of my project, but it is good info, and I'm glad to have found it. I am not an expert, and have asked a professional mechanic friend about the Gear Vendors, and he says they are great and extrememly reliable.

They sound expensive, but I figure with all the aftermarket stuff on an AOD, it works out to about the same money. And keeping the C-6 definately appeals to me, because I KNOW it is not going to fail.

thanks.

 

Hey no problem man. I've always been a firm believer in overkill, I build my trucks to far surpass the expectations I have for them in the here and now. Who knows what you might have to ask your truck to do for you in the future, its always a nice feeling to have something you can depend on to do pretty much anything.

 

If your builder is telling you they are getting stock replacement flat tops for your build you need to have them check ALL measurements carefully before they use them. The only OE flat top I am aware of was used in the HD 300's in delivery trucks and other commercial vehicles. It is only a flat top because the compression height is about .2" lower than the other pistons. This flat top gives you about 7:1 compression. A true flat top will be 2-4 points higher depending on the head you use. If they are really a high compression flat top that's great, but there wasn't an OE design that met that criteria.

 

It seems I've stirred up something regarding the flat top pistons. Let me clarify: My machinist checked his ordering book, and found some .030 over pistons available which had a high compression. I think it was 9.5:1. And I thought he said they were flat tops, but I may have misheard or remembered incorrectly.

When I take the block back to the shop to have the rest of the work done, I'll get the specifics on the pistons, and post the info.

 

Silver streak is right, all the stock flat tops were low compression [usually ~7.9:1] used from the early to mid 70's. The only high compression flat tops I've run across are custom forged pistons [not cheap].

They made an insane number of different pistons for the 300 over the years, many of which are still available. Great to have choices but it can also get confusing. You really have to pay close attention to the specs. Highest compression stock pistons were 8.7:1, but common were 8.0/8.3:1. Start with an 8.7:1 piston, zero deck the block and clean up the head and you're easily looking at 9.0:1 cr. I used the Sealed Power H519P which yields a 8.5:1 cr stock, did the minor block and head work and targeted for 8.9:1 to stay on pump gas.

 

That's right, there were a ton of them. The last time I visited the Silvolite site they had 13 OE part numbers listed. I'm going to use the early carb pistons in my build and they should give me about 10.2:1.

 

This gave me flashbacks of a headache my '89 had; something "flexing" under the dash when pushing in the clutch pedal. What it turned out to be was egg-shaped (worn-out) holes the plastic bushings use to support the horizontal support rod for the clutch and brake pedal. The clutch pedal made more noise than the brake pedal, because the support closest to the clutch pedal was more worn out than the support hole by the brake pedal. (The support rod that both the clutch and brake pedals rotate on has two holes that have nylon bushings for the support rod). The problem was noise before my engine rebuild, but with the new clutch/flywheel assembly the clutch was apparently stronger than the old one and the flex was so bad from the added strain that the worn out support couldn't activate the clutch.
Hope that isn't that same problem for you. Mine had to be fixed by the machine shop fabricating part of a new support bracket.