Technical what trans to use

Hi all i need a bit of advise i am installing a chevy small block in a 55 buick its a new 383ci crate motor and i don't know what transmission to run with it a th400 or a 700-r4 so i was hoping you guy's could help me out with your knowledge it will be running a jaguar v12 rear axle with a 3.31 ratio
any suggestion's would be appreciated

Bob

 

With your gear ratio I would run the turbo 400. Unles cruise plans are adveraging over 75 MPH

 

In the U.K., upping 75 MPH in that exquisite Buick would be like a distress call to the Bobbies: "Arrest me, Blokes...I've NO business goin' this fast!"

Beautiful Buick, BTW... I suggest Turbo 400 also. (nice with 3.30s...)
Love a pic of that Jag butt if poss...

 

700R4 will get you overdrive!!

 

If you use a 700R4 look for a 1988 to 1992 (later one would be called 4L60 but it's the same).

 

Neither. I'd use a TH350. Smaller makes it easier to install and they're great transmissions. Not a fan of either of the other you mentioned. Too much typing but the 700's too expensive to get one that's done "right", and the TH400's bulky and heavy.

 

Thanks for the suggestions men much appreciated

Atwater mike i will be posting up pictures of the build a soon as i've got the parts i need the engine has just arrived and i am cleaning up the front and rear jaguar axles for it my shops just got busy so i've got to try and fit this in as i can some long day coming i think

Bob

 

If you plan on spending a lot of time on the motorway moving fast, then the overdrive would be nice. If you're just going to drive on the normal roads, then TH350 would be my choice.

 

200-4r

 

In this application, considering bulk of the vehicle, cruise limitations and specified rear axle ratio, an overdrive make no sense whatsoever. Unneeded expense and complication IN THIS APPLICATION.

This constant chant of O/D is akin to EVERY car has to have an SBC. The O/D offers nothing unless and until one is cruising steadily above 45/50 mph unless the rear end gears are really in the basement.

I also agree the TH350 is probably the better choice. In addition to smaller, lighter, it uses less horsepower to operate it. The TH350 has long proven it's durability and would be fine in this car.

All that said, I AM a fan of the O/D automatics when the application/intended use justifies the installation.

 

Bob:
"Flyunited", "Squirrel", and "Hnstray" are all correct here: 350 would also be my choice.

I said '400', as I reasoned that you probably had a choice of only the two;

Being in the U.K. may or may not limit the availability of choice in selection of transmissions, unlike life here in the 'Colonies'...
If available, 350! My 350 T.H. has been in my truck for 175K miles, gets service every 15 or 20K...
NEVER a problem.

Man...Jag front & rear...This will be Deluxe. Can't wait to see pics.

 

thanks for all your help got a th350 on it's way as we speak

Bob