I'd like to put a TH400 in my '61 Caddy. I'm wondering if I'll have to change my drive shafts and modify the back end. Has anyone done this? Any advice appreciated.
Do a search... I would think that a TH700r4 or TH200r4 would be just as involved, with many more benefits. You will have to modify your drive shaft, ****** mount, and come up with an adaptor for any of the options, but they are doable. BRT Welcome to the HAMB, by the way
You will definitely have to modify the Cadillac driveshaft to accept the yolk for the 400. A modification of the transmission crossmember will also be required. I have a good ****** that came out of a 61 Cadillac if you just need a replacement.
Get a 55 Caddy bellhousing for a dual range hydro and put that box in the 61. At least it is a bolt in. Shifts are tight, not like dump and fill dual coupling hydro.
I believe only the '64 Fleetwoods used the early version of the TH400. Having said that, I'm not sure the early TH400's interchange with the later ('66 on?) TH400 that he would likely be using. My '64 Riviera had the early TH400, and it was problematic to find parts for at the time... Modifying the driveshaft will be the easy part of the ****** swap, IMO.
i have a 61 cad. ive got a 700r backed up to it. yes you have to modify your driveshaft and get a lock up kit and get a adapter. ive got my original motor. you cab get one threw benedettes... i think thats how you spell it. good luck bro
btw. since i have put the 700r in i have absolutly no problems. nyou'll be amazed on the gas you save. its a cruzer.
Not sure what kind of adapters would be needed to bolt a TH700R4 behind a 390 Engine(I´d like to know myself), but no matter whether You go with one of those or a TH400, You´ll most likely need to modify Your driveshaft anyway, and still only end up with a 1:1 high-gear final ratio. Personally I´d see what exactly it´d take to go with the 700. From my own experience with an ´87 Caprice over a 5-yr period, that .70 overdrive final ratio is a huge plus on highway driving...A 200K-305 V8, 4000+ lbs with two p***engers and luggage, and with the aerodynamics of a brick got it 22 Miles down the highway on each gallon, and this staying at 75MPH all day...Not to mention all the wear and tear on the engine the 30% -RPM reduction will spare you from. There are kits available from the transmission aftermarket to make the converter-lock-up function on its own without the electronic function originally in place with the ECM-equipped ´80s GM cars, without having to engage and disengage a separate switch-****on manually... Just my 2 cents...
I am looking to put a 390 with a 700R4 in my project you just need to buy an adapter plate they are pretty pricey about $800
This is where I got mine: http://www.transmissionadapters.com/Pricing.htm Article here: http://www.modifiedcadillac.org/articles/Cadillac_700R4/Cadillac700R4.html Gary
My wife is running a 8ba flathead that is backed up to a 200r. shorten drive shaft new rear end etc etc. Badaboom Badabing!!
like i said if hes got the original 390 cad motor. he wont have a problem backing up a 700r with an adapter by eather benedettes or wilcap. i have the same motor same car same ****** and i have no problems. no matter what you will need a new yolk, shorten your drive shaft etc etc.
The 64s did have a th400 but they used a buick trans with an a-dapta. in 65 they started runin the 429 motors and they are different, If you want to you can run the 64 trans on the 61 , To run the 64 stuff you need to run it all starter, flexplate, a-dapta, dust shield and machine the center of the flexplate. OH yea and the 64 trans crossmember and shorten the driveline. Other than that its a dream. Another problem with it is the cast a-dapta from the 64 hangs low and is kind quite the ***** when you shear it off 300 miles from home. I would have the slush box rebuilt. Thats what I ended up doin after all of that. Anything elese you need hit me up,
The high torque starter is totally stupid looking on a traditional Cadillac engine. It does blend with the rest of the crude looking Bendtsen's adapter though. Regards, Ron
WILCAP makes that adaptor that you need to go from your motor to a 350 or 400. Speedway also carries the WILCAP ones. The adapter kit runs around $500 and works beautifully
The Jalopy Journal
