norcal_ryan1966

Like the post says, I am trying to gauge if I should get the 4r70w transmission. The c4 in my 66 is getting pretty tired and it would be nice to have an overdrive transmission.

I have read that the v-6 4r70w transmission out of a 01 - 02 mustang is the most desireable, and has the same SBF bell housing bolt pattern as the 289/302.

1. Supposedly they can handle 350 - 400 hp stock? Is that true or just internet bs?

2. Has anyone installed one in a 64 1/2 - 66 mustang? If so, what kinds of issues did you come across?

3. Did you end up going with an electronic computer for the transmission or a manual valve body? What made you choose either option?

Thanks for the advice guys.

guitarman376

I was about to start searching for a 4r70w before I found a deal on a toploader that I couldn't pass up. I would go with a computer, that way you can program the shifts to be how you want. The OD requires a switch or button since it is electronically activated. I know that a cable shifter is usually needed, but I have heard of people making old stuff work with linkage (don't know if that's true). I know people modify fmx crossmembers to work, since the 4r70w mounts further back than an fmx. Also you would need either a shorter driveshaft or have yours shortened. Everything I've read says that they will handle pretty decent power in stock form.

fastbackford351

When my C6 takes it's final dump, I want to go with the AOD. Seems like the path of least resistance.

norcal_ryan1966

From what I've read, the aod and the 4r70w are the same transmission but the 4r70w is stronger/upgraded version/computer controlled. I am just looking for the most economical route to get an overdrive transmission in my car.

guitarman376

Forgot to mention you need a switch for the converter lockup which is worth it for mpgs in my opinion. You should read about the improvements made from the aod to the 4r. Considering they are dirt cheap in v6 fords (some v8s too w/windsor bolt pattern) to me its worth the extra money to get a computer and go that route. I was planning on going to the junkyard, taking the trans and converter (which will work btw), flush the fluid, and try it out. I'm in CA and the trans are CHEAP if you go on a sale day. Obviously this route means you have a trans jack, good friends, and some time... plus beer.

I remember reading AODs in stock fashion have some downsides to read about too, they're power limits are pretty far below 4r's from what I understand even in the v6 trans. You can get an AOD with these areas addressed, but that means paying $$ for a rebuilt one.

norcal_ryan1966

That's what I'm thinking. The problem is the trans jack, friends who are willing to help, etc. technically I'm not supposed to work on my car at my place. I can get away with some stuff, but a tranny swap I doubt it. Gonna save up and go to a junkyard, get the tranny and have a local shop I trust install it. Either that or may get a tranny/engine combo and swap the whole thing in and get a shop to do the last little things. I dunno. I'm a fan of stick shift, but thought this would be the most economical rote. Am I crazy?

guitarman376

In my experience economical and hot rodding don't co exist. Every project I've completed takes twice as long as I think it will, and about 50% more $ when all is said and done. Small things add up.

In my area it is hard to find a decent toploader for less than $1000, whereas I could get a 4r and computer for less than that and I could reuse my flexplate and modify my crossmember further reducing costs.

When I saw a toploader for $800 I had to go for it since that was about the same $ as a 4r and computer. I always wanted a stick. When I started an excel spreadsheet to determine the swap costs I soon realized it wouldn't be a cheap swap...that's how I'm justifying spending a little extra for some cool factor (aluminum flywheel, external hydraulic slave cylinder for clutch, aluminum driveshaft etc).

One day maybe I will do a 4r70w swap on a different car, but if your choices are aod or that I wouldn't think twice about the 4r70w. It sounds like any transmission swap would be tough or impossible if you don't have a solid workspace.

fastbackford351

no need to justify why you went with a Toploader. "Because it's a Toploader" is a perfectly acceptable answer.

norcal_ryan1966

Agreed. Maybe economical was the wrong word. Maybe cost effective is a better term. I just do not wanna go crazy and have to spend 3/4 k on this swap or any tranny swap for that matter.