TH700R4 Trans To 348

[BB1960]

Hi Guys,

I've got a 60 Impala with a 348 & Powerglide. I really want to fit a 700R4 overdrive trans to it, however the V8 trans are a little harder to come by (in Australia) than the V6 (which are everywhere). I'm pretty sure I cannot use the V6 unit as the bolt pattern are different...

I'm led to believe the internals are near identical...

Can anyone confirm this as the V6 700's go for a little over $100-200 and the V8 units for about $750-1000ishre.

The electronic shifted th700's are avail at $750 NEW, but I believe you need a electronic controller for it which are quite pricey.....

Forgot to meantion, it's a stocker. It's a factory 4bbl, but I have a 3x2 setup for it. The only other mods will be a baby camshaft in the future.


Any input would be appreciated.....

Cheers.


Simon

 

[Loafer409]

One thing Chevy has been good about is using the same bolt pattern across the their engines. Unless they ship some wierd stuff to you guys down there, the 700 should bolt right up to your "W" with out any problems..

edit replaced V6 with "W"

 

[dq409]

Loafer, BB1960 is bolting this up to his 348.
I believe you need the V8 700R. Some will bolt to either V6 or V8.
Look for an early one around a 1988 one. I believe you can run them without the computer but you will need to setup some type of comtrol system for the lockup.dq

Good reading:

http://www.novak-adapt.com/knowledge/th700r4.htm

http://www.montecarloss.com/SSThunder/drivetrain.html

http://www.700r4.com/faq/faq.shtml

 

[Loafer409]

dq,
I realize that he is going behind a "W", missed typed in the previous post and I assumed( you know what happens) that he was talking about a 4.3 V6 not the 60* V6, which is not compatable with the "W". Hope this didn't cause any confusion

 

[dq409]

dq,
Hope this didn't cause any confusion

confusion ??? Me???

 

[BB1960]

I think it might be a matter of getting out the meauring tape and checking the bolt patterns on the two different boxes...

 

[Firepower354]

The V8 versions do have more clutches and a larger apply piston, but the parts are swappable into a 4.3 s10/Astro van case. 94 was the first electronic controlled one so a 93-back is fine. Aftermarket brackets made for the TV cable are a big help.
Just to make it more interesting.. I prefer the 200-4r over the 700. The 2.75 first gear causes a less drastic 1-2 drop than the 3.06 and has a shorter overall length. All the cases are the same and have Chev and BOP patterns. The Grand National guys run 10's with them, with a few mods of course. Same TV cable set up. They came in tons of Monte Carlo, Regal, GrandPrix, ElCamino(ute), and some full size cars.

 

[jim_ss409]

I agree with Firepower about the 200 4R. It's got better gearing, it's about the same length as the later Powerglides, Th 350s and Turbo 400s and the mount is almost the same place as a Turbo 400. So on Chevy's built from about 66 and up it's a much easier swap because the frame is already drilled for the 400 tranny. Most of the time you can just slide the cross member back to those holes. And the length is so close that your drive shaft will usually go back in without shortening it. I don't know why they aren't more popular.
But on our X frame cars the 700 R4 might be a bit easier to swap in because moving the cross member back is a bigger job and with the 700 R4 you might get away with just slotting the holes for the mount. And because of the shorter length of the early Powerglides you'll have to shorten the drive shaft with either the 700 R4 or the 200 4R. You'll also have to different yoke with almost any swap you do because the older trannies had a different spline. They went to a finer spline in about 64 or 65 or so. I think both transmissions are similar as far as strength goes, more than strong enough for a stock 348, but both can be built to handle lots of power.
If you ask me Powerglides are only good in race cars. Even a Th 350 is a huge improvement, but an overdrive is even better, especially at todays gas prices.

 

[petepedlar]

tri power TV cable brackets

I'm getting close to bolting a 700R4 to my 409 with tripower. Can anyone suggest a supplier that would have the bracket(s) kit to fit the tri power carbs? Are there any brackets that are better than others?

Thanks for the help
Dave

 

[desapience]

Bracket kits...

I'm getting close to bolting a 700R4 to my 409 with tripower. Can anyone suggest a supplier that would have the bracket(s) kit to fit the tri power carbs? Are there any brackets that are better than others?

Thanks for the help
Dave

Dave

I have a 700R4 (converted to non-electronic), bolted to my 446 stroker. Excellent, strong, and the lower 1st gear is not a minus, but, a plus, IMO. You can run a tall 3.0 or 3.23 rear gear, and still come out of the hole with a hellish vengence, while maintaining a nice easy lopping engine at 60 mph, in overdrive/lockup.

I used a Lokar carb-bracket set-up for the TV cable (which is actually a pressure-pump regulating device, not a kick-down cable). But, you can use the stock GM bracket typically found on the TH350's for their kickdown cable (mounts on the intake manifold), and can be purchased almost anywhere.

As for ways to connect the cable to your center carb, there are various sized ball-studded screws that come with Holley carb kits, Edelbrock carb kits, etc., and can be bought separately... I really don't see where there would be any difficult problems here at all to solve.

Denis

 

[petepedlar]

TV Brackets

Thanks Denis,
My 409 , probably about 325 H.P. & gobs of torque is going into a 38 Chev 2 dr sedan with a 9" posi & 3:55 gears. With the 700R4 it should work very well as a nice cruiser and still haul it's butt off the line when I want it to.
I have the stock cable with the transmission and a stock bracket should be easy to find. With all I have read about swapping a 700R4 I and getting that cable set properly I thought I would be better if I could get an aftermarket mounting bracket and something that fits the linkage arm on the carb for the ball stud so that all the leverages, distances etc. were correct.
I'm just a little worried that adapting something might take out the transmission down the road sometime.
Do you know of a kit that's available? I'll check Lokar & see if they have anything for the tri power. Am I worrying about something I don't have to?

Thanks
Dave

 

[rwagon57]

Pete,

I really don't think the 3X2 set up makes any difference. The Lokar TV cable is a quality piece and should work fine. For your peace of mind, do a web search for 700R4 TV Cable and you should find some drawings and other useful information that will show exactlay what the geometry needs to be. Again though if you use the Lokar kit and follow their directions you should have no problems.

 

[desapience]

Lokar has everything you need!

Thanks Denis,
My 409 , probably about 325 H.P. & gobs of torque is going into a 38 Chev 2 dr sedan with a 9" posi & 3:55 gears. With the 700R4 it should work very well as a nice cruiser and still haul it's butt off the line when I want it to.
I have the stock cable with the transmission and a stock bracket should be easy to find. With all I have read about swapping a 700R4 I and getting that cable set properly I thought I would be better if I could get an aftermarket mounting bracket and something that fits the linkage arm on the carb for the ball stud so that all the leverages, distances etc. were correct.
I'm just a little worried that adapting something might take out the transmission down the road sometime.
Do you know of a kit that's available? I'll check Lokar & see if they have anything for the tri power. Am I worrying about something I don't have to?

Thanks
Dave

Dave,

Lokar has everything you need. Setting the cable tension is very simple.., you always leave it adjusted with a slight slack in the closed throttle position. You never tighten it taught in the closed throttle position.

Lokar has the entire cable assembly (which I also have in my '55' belair), the brackets (sold separately), and, if I remember correctly, even the t-head screw connector for the cable (at the carb) comes with the cable. It comes with plenty of extra length to the cable to adapt to your needs..., just a bit of a trick to cut it correctly without fraying the entire thing.

Because of the angle you'll want the cable to approach the center carb, I'd advise you to consider adapting a Lokar bracket (or fabricate your own) to mount in the position that the stock TV cable bracket mounts to the intake.

A quick fab job would be to get a stock bracket, weld a cap on it's opening, drilled through to fit the Lokar cable adjuster..., you can even slot the top edge of it, so you can dissasemble it and remove the cable without removing the bracket.

Hope this helps.
Denis

 

[BB1960]

Well,

I've finally bought the 700r4 (thanks for the recommendations for the 200R4 but we never got them here in Australia).

Now I'm looking at 'engineering' the TV Cable. Luckily the engine, carbs and trans are all out of the car which will help a little.

I'm looking at the Lokar kit, has anyone had any experience fitting this??

The 2GC centre carb I am using has a hole in the throttle bracket that looks pretty close to what I need (I think about 1.1 inches) but haven't checked the alignment yet....

Does anyone have any photo's of a 3X2 that has a 700R4 in it???

Cheers,

Simon

 

[62wagon]

Simon - I have a 700r4 behind the 348 in my '58. I am running a TV setup from BowTie Overdrives - http://www.tvmadeez.com/tri-power_sbc/ - It seems to work pretty well. It has plates under each carb. The front two carb plates act as spacers while the rear plate has the TV cable attaching point and an accel cable point if you would like to use it. I am attaching a picture that shows it but not great. I can e-mail you a higher res picture if you would like that you can zoom.

Mark

 

[BB1960]

Mark,

Thanks for the picture and the info. I saw that kit for sale, however it doesn't say anything about being suited to the 348 3x2.....

I 'think' I had also read a negative review on this kit, but if you are running it and it fits and works, I'll take that as the thumbs up!!!

Cheers for the help, I wasn't sure which way to go, but am now!!!!

 

[BB1960]

Thanks for the reply and the photo. If you have a chance (and a camera) would you be able to take a closer-up photo of the TV cable you have. I'm interesting in seeing where it attaches to the carb.....

cheers.

Simon

 

[62wagon]

Simon - I would be more than happy to if you can give me a couple of days. The car is currently at the interior shop. I will be going there Thursday on my way to the Goodguys show this weekend and I can post it on Monday. As far as your previous reply, I can not say complete thumbs up yet as the car has not been highway driven yet. Initial impression is that it is going to work just fine. They are super nice and informative at BTO, so e-mail or call if there is anything real in-depth you might need. I'll talk back soon.

Mark

 

[BB1960]

Thanks heaps mate.

I'm dummy mocking up the block and trans soon, so once the crossmember has been made I can start looking at making the tv cable.

A closer look at one already done would hopefully speed up the process.....

Cheers,

Simon

 

[62wagon]

Thanks for the reply and the photo. If you have a chance (and a camera) would you be able to take a closer-up photo of the TV cable you have. I'm interesting in seeing where it attaches to the carb.....

cheers.

Simon

Simon,

Do you remember typing this? It has been a while so think back real hard. Anyways, I finally was able to get you a picture. If you still need it, hear it is and I apologize for the delay. Hope your project is coming along.

Mark