700r4 Behind /6?

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JBAR

JBAR
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I have seen adapter plates for the swap, but cant find any one that has done it, or where to find info on how to. Help me if you can:scratch:
 
JBAR said:
I have seen adapter plates for the swap, but cant find any one that has done it, or where to find info on how to. Help me if you can:scratch:
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Where have you seen the adapter plates? They are available for the V-9, but I don't know of any for the slant six.
 
Wilcap makes a /6 to a GM turbo 350 adapter, a 700r4 with the same GM pattern as the turbo 350 would bolt right up as would any GM auto trans with the same pattern.


Chuck
 
I, too, would be interested in anyone's experience with this swap. Since they make the adapters, maybe Wilcap would know...?

I have the bellhousing for the T-5 swap, but my Swinger's an auto, and it seems like a 700R4 might be a MUCH easier way to get overdrive (although without the fun of shifting my own gears!).

VM
 
the adapter seems like the easy part. its the k/d cable that is going to be fun. make sure you use the later style 700r4 with 30 splines not 27. 27 splines were made for 3 years only, 84-86. also use a painless lockout kit with a lokar k/d for smooth running.
 
I wouldn't even use a 700r4 at all. If I was to use a GM trans it would be the 200-4r, it is a much stronger trans than the 700r4.

Here's food for thought that maybe some tranny guy could answer. Why couldn't someone put the A500 guts and OD unit in a /6 904 case?


Chuck
 
Just a couple points. The 200 is the weak tranny. The 700 later became the 4l60e which is used in trucks and cars. Many engineering changes have made it a better tranny but I still don't care for it.

The question of putting the A500 guts into the /6 case, no problem. Until it comes to the rear support, O/D piston, retainer and the O/D tailshaft unit. The rear of the case is very different to accomodate the O/D. It would be easier to contact JW Transmissions and see if he makes an Ultra Bell for the /6 conversion or an adapter.

I've also seen where Keisler is marketing a 4l60e conversion kit that doesn't require modifying the floor pan. I'm not sure if it's for big blocks or small blocks or both but I'm sure it's costly.
 
actually, chuck is right. the 200-4r is a stronger tranny. they did an article in drive! awhile back that had 3-4 tranny shops talk about overdrives and all say that the 200-4r can take more hp than the 700-r4. yes the 700 did become the 4l60e, but even then the vette got the 4l80e. the gnx cars got the 200-4r, and that car outperformed the vette. beside all that, is a slant 6 gonna kill a 700-r4???? NO.
 
Personally i dont care for the 700r i have seen many of them trashed in normal driving. Not trying to steer you another way just trying to let you know my experiences. With a rebuilt 700r and a slant 6 you probably wouldnt have problems i just dont personally care for them. Good Luck Justin
 
redfastback said:
actually, chuck is right. the 200-4r is a stronger tranny. they did an article in drive! awhile back that had 3-4 tranny shops talk about overdrives and all say that the 200-4r can take more hp than the 700-r4. yes the 700 did become the 4l60e, but even then the vette got the 4l80e. the gnx cars got the 200-4r, and that car outperformed the vette. beside all that, is a slant 6 gonna kill a 700-r4???? NO.
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I've done both of them, though it's been a very long time ago. I remember the 700 as being kind of light duty but the 200 didn't impress me as being any better. It had a screwed up valvebody arrangement that was very sensitive. Maybe it's stronger but I can't see why. But what it was used behind, or in, isn't necessarily an indication of it's torque rating. And that is what is the determining factor for it's application. Gearing, both trans and final drive, vehicle weight, platform packaging and intended application all factor in along with engine output to determine what trans is used.

As for which is the better trans? Does GM still make the 200?

On a side note I just overhauled a 4l60e from a 350 v8 pickup with over 340,000 miles on it. It was none the worse for wear and only required friction plates, seals and gaskets.

I'm not sure but isn't the 4l80e just a beefier version of the 4l60e? I'm not really up on GM's.
 
Why go through all the hacking and headaches to wind up with a POS GM tranny, when all you have to do is bolt a Gearvendors overdrive unit to your 904 and shorten the drive shaft? You will wind up with a 6 speed auto for about the same money. Just my $.02.
 
grumpuscreature said:
Why go through all the hacking and headaches to wind up with a POS GM tranny, when all you have to do is bolt a Gearvendors overdrive unit to your 904 and shorten the drive shaft? You will wind up with a 6 speed auto for about the same money. Just my $.02.
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Because:

A) The extra length of the GV unit creates problematic pinion angles in cars as short as A-bodies. Longer cars like B-bodies, not so much.

B) The GV requires trans tunnel modifications to fit (real "hacking"), where as I think the 700R4 wouldn't. Crossmember mods could be reversed by replacing the crossmember with an original. What other "hacking" are you referring to?

C) GV aren't cheap, and allowing the driver to manually split gears doesn't result in a 6-speed auto. Talk to a few owners — NONE seem to split gears on a regular basis (it seems to require a LOT of practice and coordination). The owners I've talked to just activate the unit and use the it for overdrive.

D) The GV is only .78:1 overdrive, as opposed to the 700R4's .70:1. I'd prefer as much overdrive as I can get for the money.

I'm not against GV overdrives, but there are alternatives to consider as well.

VM
 
yeah a 4l80e is just a beefier 4l60e. i guess either way, the 700 or 200 will both do the job fine behind a slant 6 and way cheaper than a gear vendors. the one thing i don't like about GV is the manual/auto OD button setup and the gobs of extra wiring that go under the dash as well as the 2k to buy it.
 
The reason the 200-4r is gone is because there are no more rear drive Buicks and GM diesels. The Grand National used the 200-4r which is the highest output of any GM car in the 80's. Buick has a history of using only the best parts in there cars. The GN Buicks even had rearends that no one else put in there "G" bodies. I have seen may GN & turbo Regals run low 11's with the 200-4r and have not seen on 700r4 in a car that ran faster than a 13. Maybe I am a little biased being I am an old Buick guy, but have experienced both trannies.

To me all of the GM trannies are barely worth the aluminum they are made out of now.

Chuck
 
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