Hello I am new here. I recently just purchased a 1967 Cadillac Sedan Deville that has a 425 motor in it. I am loving the old boat! The motor has a few miles on it and its running pretty rough but the rest of the car is in perfect condition. My friend has a Cadi 472 motor that we wanted to put in my car. I want to use the same transmission that is bolted to my 425 if that is possible? My question is will this motor go in without any modifications? Also will the tranny bolt up with no issues? Please Help! Thanks alot!

I would think that the transmission is a TH400, same as previous years, so that should be OK with the 472/500 series. other folks here may be more familiar with the engine mount similarities, but I suspect the basic engine is a bolt-in. Accessories mounting ?? don't know.

Maybe you can do a search on here, and turn up more info.

1967 should be a 429 if it's from the factory. It's completely different than a 472. Where a 425 and a 472 use the same block and would swap very simple. The 425 wasn't introduced until 1977 and the 472 in 1968. But the '68 and the '67 share a very similar body and I would assume frame, so maybe the motor mounts and other parts from a '68 would work? I'm not sure about the tranny, but I don't think it will bolt up.

I would think the swap would be fairly easy although I don't have any first hand knowledge about it. If I had a 67, I would be looking to put a 472/500 in it. GM made the TH400 at least as far back as 66 so I'm sure the Caddy's would have used them. My love affair with Cadillacs started with my best friends 67 Deville in high school; that was a cool classy car. We were young and couldn't keep it running though. It did make a very cool smoking lounge.

I don't remember when they quit using the two-coupling "jetaway". I had a '67 Bonneville up until a few years ago, with a TH400 in it. I had a '65 DeVille, but don't remember what trans it had. Maybe the move is to identify the trans before planning a swap. There's diagrams of the oil pan bolt pattern for identifying which trans it is. My money is on the 400:cool2:

I could be wrong though, I was once in 1947.;)

According to this Cadillac book I have, it says that in '64 the turbo-hydra-matic became standard, but it doesn't specify the model.

According to this Cadillac book I have, it says that in '64 the turbo-hydra-matic became standard, but it doesn't specify the model.
I think the THM became standard for all Cadillacs in 1964 except for the Fleetwood Seventy-Five series (9-passenger sedan and Limousine).

The 67 has a THM400, switch pitch version. It has a bellhousing that only fits the 429 engine. I believe you could redrill 2 of the 6 holes, and it would fit the 68 or later engines. Or you could rebuild the trans into a newer case, not a bad idea if it is original & preparing for a bigger engine. I have a few comments on that on my photo bucket site, user bcroe.

Most likely you will need to rework some accessories; try Maximum Torque Specialties about engine mounts.

Bruce Roe CLC 14630 Advisor

Have you made a positive ID on the motor yet? If it really has a 425, then someone has done the dirty work for you and left you able to make the swap with few mods (if any). If it is the factory engine, then it is a 429.

Hmmmm,I would find the block casting and head casting numbers and post them here.If it's a 429,then there will be a little work involved to make the swap work.

I believe a 429 has a large aluminum front cover; 500/472/425 are block casting with a flat steel plate. Bruce Roe

I overhauled the 429 in my '65 DeVille, but that was ages ago, and the only thing I remember is that the oil pump is on the front timing cover, like the later 472 etc. Had to remove the pump once because of a stuck oil relief plunger.

If I remember correctly, the 429s had Cadillac scripted beautifully on the valve covers in large gold or yellow lettering, but all 425, 472 and 500 engines had nothing on the valve covers. I don’t know if ALL 429s had Cadillac on them, but if yours does, then I’m guessing 429

If I remember correctly, the 429s had Cadillac scripted beautifully on the valve covers in large gold or yellow lettering, but all 425, 472 and 500 engines had nothing on the valve covers. I don’t know if ALL 429s had Cadillac on them, but if yours does, then I’m guessing 429

the 390 and 429's had the valve covers with Cadillac script on them,425,472,and 500 didn't have any script on the valve covers.So,that is correct as far as I know

If I remember correctly, the Turbo Hydramatic was developed around the Buicks, and the "switch pitch" was one of their things to begin with. Anyone know about that ?? ......Bruce ??

Just wondered, since this thread reminded me of it.........:hmm:

A stock 67 Cad has a switch pitch TH400 or TH425 trans. The engine has a 3 wire switch by the carb to control it (2 wire in 68 up). Doesn't bolt to anything else, unless you redrill a couple holes. The 67 has distributor plugged into aluminum front cover; 68 up has it into iron block, cover is steel. I believe 67 has exhausts siamesed in center; 68 has 4 ports in linear fashion. Bruce Roe