i go down to the Mopars on the Mississippi show every year... Do you just put an overdrive button in the car?

He's normally in a swap space with the tranny stuff, he was there last year at the end of the concrete to the north.

I have 2 toggle switches, one that turns both OD and lockup off and one that just kills lockup. With my 3.91's and 28" tires, I've found that setting it to auto shift into OD at 45-50mph is right, and around town I leave lockup off, otherwise it tends to bog too much. Newer engines are designed to trot around town at 1200-1500rpms, 40yr old big blocks aren't.
There are adjustable pressure switches to get it to shift at whatever mph you want. I shorted out my 2nd one, but I had it shifting into lockup about 60mph.

Thanks Furious70, hope to see you at Dubuque. I put bigger tires on my Cordoba 275/60 and it killed my TQ lockup.. it has been around 35 it dropped to just under 30.

Not sure I'll be there this year, got a 6 month old baby keeping us busy!

'gear it and be done with it'? I'd much rather have the extra tranny cog and have the best of both worlds. Coming out of the hole with the equivalent of 4.30's and then cruising with 2.68's + lockup sure is nice.....

Just the gear ratio differences between the 700R4 and the 518 would make me want to swap. In the early 90's I ran a Dynamic built 700R4 behind a 454 nitrous motor in a Caprice w/o problems, sold it 3 years later. I understand totally why someone would rather have a gear ratio like in the 700R4 3.06 1st, 1.63 2nd, 1 to 1 than 0.7 OD compared to a 518 which is 2.45 1.45 1 than 0.69. The difference is unreal and that's where things get interesting. With the 700, you can actually run 3:23's and first gear seems like 4:88's, not so with the 518 which has a 2.45 first gear and you'll know what its like to run 3:23's with a 727, doncha?

Purists are hard to educate no matter what the subject whether it be Mopars or Harleys, Chevys or Fords. Me, I just wanna go fast, be comfortable and enjoy the scenary.

IMO, The large spacing between 1st and 2nd makes the 700R4 a poor choice for a performance trans. Going from the 3.08 first gear, a 6000RPM shift drops all the way to about 3200 in 2nd. I prefer a well prepped 200R4 over a 700R4. The 200's ratios are 2.74/1.57/1.00/.67 which gives you a good low gear, less RPM drop, and a small package. And either one needs modified or aftermarket hard parts to live behind 500HP engines. The only good reason to consider one in a Mopar is they are a smaller, shorter package to fit in the tunnel.

the 700r4 is based off the turbo 350.

install a gear vendors behind that 727. thats what Im doing.

the gear vendors turns my 4.56 into 3.55 I have a 31 tall tire too.

The above posts are the reason I have a heavily beefed a500 in my car, low gear set, smaller package, and lockup. It would need more beefing to live behind 500+ hp, but can be done and you're still using a mopar tranny.

Gear vendors does not make a unit for my particular 727 which is a 62 BB push button as I have discussed this transmission with them twice in the past 10 years. Never the less and quite the contrary to what you believe, the 518 is outdated and has never been a strong transmission although its roots are from the 727. I went through this in 1992 with the second engine in this car. Anyone here remember where they were in 1992?

I checked into the 545RFE and the 68RFE transmissions which are used against the 5.7 Hemi to be used in my vehicle and both are just too temperamental for my pockets.

Quote from Hot Rod Magazine: Some swaps have used a Chrysler A-518 four-speed automatic overdrive. Although it's the same length as an A-727, the A-518 is a lot fatter. The mount pattern is the same as a GM trans, and a GM TH350 mount is recommended. One advantage of this beefy A-727 descendent is that it does not require a computer or lockup converter, and Overdrive can be actuated with a simple toggle switch. On the other hand, the bulky trans requires major floorpan surgery. Even bulkier is the stock late-model 45RFE electronically shifted trans. It needs its own separate trans controller in addition to the stock engine ECM. A possible alternative is Keisler's new Chrysler overdrive trans conversion kit, which uses a more compact GM 4L65E four-speed automatic with an aftermarket standalone trans-controller.

The above is the reason for using another manufacturers transmission but yet the only hard part for some is to use common sense.

I'd go into gear ratios further but I've simply lost interest in arguing true facts.

this is a great article: http://www.popularhotrodding.com/tech/0908phr_keisler_a41_automatic_transmission/index.html

I have a lot less money in mine, and I didn't do the install, the tranny shop did. And it has a bolt on bell. I don't have fancy paddle shifting, and it does rely on a tranny guy knowing how to correctly tune the VB vs. electronics, but for $2000 less, I can certainly live with that.

Ultra bell is cheaper and you don't have to grind the block. From what I seen to run the 500/518 trans behind a BB with an adapter you need to grind the block rear ear off below the starter.