[ClassicDriverMan]

Hi all,

Doing some research... Have read tons of stuff about adapting a 700r4 to the Pontiac BOP, early Pontiac blocks with adapters, etc, etc...

But my main concern that was mentioned but not elaborated on was the size of the 700r4 trans and that the tunnel would have to be hammered to get it in a 55-57 Pontiac. Is that true? The original hydro is pretty big, but I don't have any measurements for the 700r4.

I will be running a 455 (400 block - stroked). Not a really high HP motor. Just a cruiser with a fair amount of torque. Iron heads (for now) with an Edelbrock performer intake, cam. It should be close to 400hp and around 450lbft of torque.

So my question are:

1. Will the 700r4 fit in the 57 Pontiac with no tunnel mods?
2. Would I be better to go with a built up 200-4r?

Any input would be appreciated.

Thanks.

[pfilean]

Having not done such a conversion I will only be speculating. But my thought is yes it will fit. It is well known that for the 61-64 Catalina/Ventura/Grand Prix that got the Slim-Jim there are interference problems with the floor hump. But the same years of Bonneville that got the 4sp HM don't seem to have the problem. Perhaps the space needed for an adaptor that moves the transmission rearward slightly could make some problems. But in any case most seem to think they solved the issue with the BFH treatment. Would probably work the same in the earlier models just as we'll.

I think the 200 may be a little smaller than a 700. You may find the many posts from Wilmington in the 62-64 forum helpful. He is just finishing putting a 200 in where a Slim-Jim was and has some insight on size and interference.

[pfilean]

Messed that one up-he is Willshire not Wilmington.

[ClassicDriverMan]

Thanks for the reply. Yeah, I have read about swapping the trans on later models like the Catalina/GP vs the Bonneville. I guess since the Bonnevilles had the HM, I would hope the tunnel is close to the same.

Hopefully someone will chime in with a 55-57 Pontiac and tell about swapping in a 700r4 or 200-4r.

[U47]

Originally Posted by ClassicDriverMan

Thanks for the reply. Yeah, I have read about swapping the trans on later models like the Catalina/GP vs the Bonneville. I guess since the Bonnevilles had the HM, I would hope the tunnel is close to the same.

Hopefully someone will chime in with a 55-57 Pontiac and tell about swapping in a 700r4 or 200-4r.

Just a FYI both a Roto and a Super-HydraMatic are referred to as HydraMatic. I have a Long shaft T-400 going into a 62 Cat and have conflicting stories from people who says their's fit with no problem, while others say a little surgery is needed. I will have to see about that. If I had a good Super HydraMatic and could be mated successfully to a 69 428 I would go that route. You can use even a 2.69 diff and still have great acceleration because of that 3.97 first and 2.55 2nd gear, and in fourth gear you have split torque for great economy....almost as good as a converter with lock up, but better than a 200 or 700 without the lock up.

[ClassicDriverMan]

I didn't know they were both (roto and super) referred to as HydraMatics.

Anyway... Has anyone put a 700r4 or 200-4r in a 55-57 Pontiac? Will I have to beat up the tunnel to make them fit?

[U47]

Originally Posted by ClassicDriverMan

I didn't know they were both (roto and super) referred to as HydraMatics.

Anyway... Has anyone put a 700r4 or 200-4r in a 55-57 Pontiac? Will I have to beat up the tunnel to make them fit?

My 1962 Pontiac "HydraMatic" service manual covers Roto and Super HydraMatic. Both transmissions are built by HydraMatic Division of GM.

[ClassicDriverMan]

Thanks for the input.

Anyone actually put a 700r4 in a 55-57 Pontiac? And if so, any tips on shifter linkage and fitment issues?

[ClassicDriverMan]

Anyone? What about anyone have any measurements of a 700r4 vs Dual Coupling Hydramatic?

[b-man]

700R4 dimensions: http://www.tciauto.com/tc/trans-dim/

[Bill Eveland]

If there was a side view comparison between a short tail th400 like in mine and a 700r4 I think that would a little better maybe. I have my engine over an inch higher than stock and have over an inch between the top of trans and tunnel near the back. I did flatten out the flange that sticks out of the bottom of the firewall.

The 200r4 may be a better fit and wouldn't require an adapter.

[ClassicDriverMan]

A side view would be the best. Length is helpful, but I need to know how "fat" and "tall" the 700r4 is?

[Bill Eveland]

Saw this , scroll down about halfway for the comparison pics. Looked pretty similar in size. Had some pretty good info also if you still want the 700r4.

http://www.rowand.net/Shop/Tech/Auto...issionSwap.htm

[ClassicDriverMan]

Thanks Bill. That is great information. And you have room even with your motor/trans raised and off to the passenger side... I feel that is should fit.

Have any suggestions for the shift linkage set-up? I want to make it look stock. I am planning on keeping the column shifter.

[Jack Gifford]

There probably isn't a practical way to match up your column shifter's gates and indicators, since the 700R4 valve body has four separate forward positions. Personally, I wouldn't worry about that- just hook it up to your column and shift by feeling the detents in the transmission's valve body (and mentally count-off the "clicks"- P, R, N, 4, 3, 2, 1). I've done this with a number of trans/car combinations.

[Bill Eveland]

Lokar makes a column cable shifter kit for a 55-7 Chevy, might want to look into that to see if it would work.

http://www.danchuk.com/ItemForm.aspx?Item=12590

Even though the engine is off to the side and up some, I still have to have it line up with the center of the x member. I'm running a b&m floor shifter. I had it working with the 55 bench seat but it was a tight fit. I've switched to racing style buckets seats and moved it back some.

[ClassicDriverMan]

Originally Posted by Jack Gifford

There probably isn't a practical way to match up your column shifter's gates and indicators, since the 700R4 valve body has four separate forward positions. Personally, I wouldn't worry about that- just hook it up to your column and shift by feeling the detents in the transmission's valve body (and mentally count-off the "clicks"- P, R, N, 4, 3, 2, 1). I've done this with a number of trans/car combinations.

Thanks!

Originally Posted by Bill Eveland

Lokar makes a column cable shifter kit for a 55-7 Chevy, might want to look into that to see if it would work.

http://www.danchuk.com/ItemForm.aspx?Item=12590

Thanks for the tip...

[Goatracer1]

I put a Turbo 400 in my 1957 Chieftain with no trouble. Combined the shift linkage from the T400 and the 1957 column shifter. Changed the shift indicator. Only problem was the neutral/backup lt switch. Used a street rod switch that mounts on the trans. T400 shouldn't be smaller than your OD trans.

[ClassicDriverMan]

Originally Posted by Goatracer1

I put a Turbo 400 in my 1957 Chieftain with no trouble. Combined the shift linkage from the T400 and the 1957 column shifter. Changed the shift indicator. Only problem was the neutral/backup lt switch. Used a street rod switch that mounts on the trans. T400 shouldn't be smaller than your OD trans.

Hey, Thanks! Great info.

[d2_willys]

Originally Posted by Goatracer1

I put a Turbo 400 in my 1957 Chieftain with no trouble. Combined the shift linkage from the T400 and the 1957 column shifter. Changed the shift indicator. Only problem was the neutral/backup lt switch. Used a street rod switch that mounts on the trans. T400 shouldn't be smaller than your OD trans.

Did you keep the 347? If so did you use an adapter? The Pontiac engines from 55 to 60 do not have the BOP pattern, except for the two top bolts.