Automatic Overdrives for big blocks: Who has one? Costs? Drawbacks?

[Kern Dog]

Hey guys,

Every so often I get the bug to spend some money on the car. Since 2006  I have wanted to make my Charger more fun to drive. Like almost everyone with a classic car, I have a newer daily driver with an overdrive transmission. The reduced engine speed sure makes for a more comfortable ride.

I have a 440 based 493, a 727 and an 8 3/4 axle. When I first built the car I had a 4.10 diff. It would scram up to freeway speeds but any sustained freeway drive felt like driving a low geared Power Wagon from the 60s. I installed a Gear Vendors and a 3.91 diff and while the meager .78 overdrive did help, I just wasn't fully happy with the performance of that setup. I currently am back to a direct drive 727 setup with a 3.55 gear. The car performs great but the allure of a decent .70 overdrive gear keeps calling me.

I don't want to switch to a manual transmission. I like the automatic for many reasons.

I have a friend that installed a 618 trans in his 70 Cuda. The car had a mild 440 but he wanted the added durability that the Diesel spec 618 had as compared to the 518. He has said that he was never fully happy with the transmission partly due to the mods associated with the bellhousing.

I have seen some make mention of the GM based 200 4R. This trans is supposed to be capable of surviving behind high HP engines but also seems to share the same fate as others: It needs a replacement bellhousing. To me, this means that it shares similar drawbacks as the 500/518/618.

So far, the only option that I see that comes close to what I want is the 4L60E setup from the guys that replaced Kiesler: Silver Sport Transmissions.
I see that some have gone that direction. I am curious as to several aspects of this swap.

Which kit did you buy?
What was the price?
How long was it from the time it was ordered until it was delivered?
Was the driveshaft included? Did you have to mock it all up then call them with the measurement?
How did they address the stock floor shifter to operate the transmission?
Were there any problems with fitment?
How is the downshift/kickdown function controlled? Cable or electronically?
Is the converter lockup switch operated or automatic?
How is the feel? The 1-2 upshift seems to be big with the huge ratio difference of 3.06 to 1.62.
Any drawbacks?
Thanks everyone.

[fizz]

I went with one, don't have my paperwork in front of me, but as follows:
Higher torque rated trans, think it was 650 ft. lbs
About $6500
Was here in about a week after I pulled the trigger
After install, called in dimension, driveshaft here in a week.
Roll pinchweld from tunnel to firewall up tight, then no fitment problems
Cable kickdown, sent all bkts, I made my own bellcrank and cable bkt, just cleaner IMO
Automatic converter lockup, trans is tuned so it pretty much only locks up in hiway operation
you can tune how all everything feels pretty much infinatly, go with the laptop tuning
The kit is complete with good install instructions
Their kit is cable shift modified to fit the stock shifter. I installed the throttle position sensor on the shifter, used opportunity to rebuild shifter with tighter bushings. Kit has new detent plate so you have shifter positions to include overdrive
Their techs are awesome
Jack Silver called me personally to see how I like the kit
Maybe, you would rather get a converter from another source, No probs, stall speed question.
I have said it before, this trans made the car, 391 rear gear performance, 2500 rpm on interstate
I had to modify the right hand collector on the TTI headers to clear the deep, cast trans pan(pie cuts and reweld to turn it)
I have 2800 miles on it, lots of burnouts and beating on it, no problems.
My engine is 505/550 at the rear wheel.
I would never drive this car the way I do without this trans. I would have no problem taking off cross country. Intend to do powertour this year.
I have many install pics, they have an install manual you can look at online.

[cdr]

as you know I have the 518, the bell housing is not an issue, cars with over 1000hp run the jwbell, they use them on th200,700,th400, powerglides ect. 3.54 gear & .69 od is awesome.

[flyinlow]

What I want is a ZF eight speed with a 3500rpm stall converter with lock up. What I have is an A518 / Ultra bell. Single best performance up grade I have made. (73 Charger/ Mild 446/ 3.55)


Used 94 3/4 ton van low mile 3 wire A518 trans, Ultrabell , shift kit , new driveshaft, misc.  about $1200 eight years ago.

Drives like a torqueflight, if you like that, I do. I flip switches for OD and Lock up. A vacuum switch unlocks the converter at low vacuum setings in case I forget.

35,000 + miles so far.

2.77 first gear sets are avialable.....on my list for the next car. Will be putting one in the "70 , probably more fitting issues.

Minor fitting , fabricate trans crossmember ... with carpet and and a Hurst shifter you don't notice.

Full Weekend project with a lift and two guys.

[darbgnik]

I just picked up a 3.55 sure grip center section to replace the 4.10 in my car now, that's behind the 727. The Silver Sport A41 transmission has been on my mind for a while now, but I'll see how just the gear set works. Bonus that the A41 will read off of a 0-5Volt TPS, as I plan on either the FITech or Holley Sniper fuel injection this year.

[Brass]

the allure of a decent .70 overdrive gear keeps calling me.

Right?  I don't understand why Gear Vendors didn't make their overdrive .69 instead of .78.  Or provide their customers with more than one option.  It would be great if they eventually did that.

[flyinlow]

Right?  I don't understand why Gear Vendors didn't make their overdrive .69 instead of .78.  Or provide their customers with more than one option.  It would be great if they eventually did that.

[Kern Dog]

I would take another look at a Gear Vendors of they did have a better ratio. The unit I had was a rebuilt first series version. It had no provisions for the floor shifter brackets, the electronics were not consistent and it had a bolt on yoke instead of a fixed yoke.

[fizz]

Sorry for misinformation, Kickdown on Silversport conversion is electronic, throttle position sensor is cable.

I did not do gear vendors because of problems I read about, including driveline vibration and troublesome electronics

[John_Kunkel]

I don't understand why Gear Vendors didn't make their overdrive .69 instead of .78.

The Gear Vendors unit is actually derived from the old Laycock de Normanville overdrive used on British cars, Volvos, etc. Dates from the fifties (or earlier)....I had one in an Austin-Healey.

[Brass]

Here is the Gear Vendors rationale for the .78 ratio from their website:  

"With the .78 to 1 ratio you're good with any torque converter you choose for high performance street/strip use."

Meh.

[Mike DC]

  
Mopar didn't make a B/RB overdrive (automatic) tranny.  So any possible OD auto retrofit option (besides keeping the stock 727 and using a GV) means a swapped bellhousing in some form.

The question is how it's done.  The A518's method is not as bomb-proof as the GM retrofit ones.  But I have never heard of one breaking.  It's more of a peace-of-mind problem AFAIK.  


The A518s have the tranny oil pan (and the valvebody inside it) protruding down about 1" below the 727's pan.  That is a factor for street cars.

[flyinlow]

I had reservations about the JWultrabell bolting to the pump, but it has worked well so far.

The kickown is a modified stock one piece rod . 1,2,3 gears are like a normal SB 727  (pound the crap out of them) Overdrive and lock up are for cruising. Manual with switches.  I have never subjected the overdrive to extended WOT big block torque levels. The A518,700r4, 200r4 and 4l60 overdrive thru a planatary gear set in the tailshaft. A power drain and potential weak spot for extended NASCAR/Autobann use. (OK, it could happen)

[frank1966]

I went with one, don't have my paperwork in front of me, but as follows:
Higher torque rated trans, think it was 650 ft. lbs
About $6500
Was here in about a week after I pulled the trigger
After install, called in dimension, driveshaft here in a week.
Roll pinchweld from tunnel to firewall up tight, then no fitment problems
Cable kickdown, sent all bkts, I made my own bellcrank and cable bkt, just cleaner IMO
Automatic converter lockup, trans is tuned so it pretty much only locks up in hiway operation
you can tune how all everything feels pretty much infinatly, go with the laptop tuning
The kit is complete with good install instructions
Their kit is cable shift modified to fit the stock shifter. I installed the throttle position sensor on the shifter, used opportunity to rebuild shifter with tighter bushings. Kit has new detent plate so you have shifter positions to include overdrive
Their techs are awesome
Jack Silver called me personally to see how I like the kit
Maybe, you would rather get a converter from another source, No probs, stall speed question.
I have said it before, this trans made the car, 391 rear gear performance, 2500 rpm on interstate
I had to modify the right hand collector on the TTI headers to clear the deep, cast trans pan(pie cuts and reweld to turn it)
I have 2800 miles on it, lots of burnouts and beating on it, no problems.
My engine is 505/550 at the rear wheel.
I would never drive this car the way I do without this trans. I would have no problem taking off cross country. Intend to do powertour this year.
I have many install pics, they have an install manual you can look at online.

[/quote

Hey, you bought the silversport r sp auto? Just curious why not one of their manual tranny? Trying to decide on manual vs auto

[John_Kunkel]

I had reservations about the JWultrabell bolting to the pump, but it has worked well so far.

The clutch automatics (Clutchflite, Clutch Turbo, etc) proved that the pump bolts are up to the task.

The A518,700r4, 200r4 and 4l60 overdrive thru a planetary gear set in the tailshaft.

Only the 518 has the OD in the tail, the GM OD is internal....that's why they're more compact and easier to retrofit.

[fizz]

My only wretched reason for going auto was the cell phone glued to my ear.