News:

Due to a technical issue, some recently uploaded pictures have been lost. We are investigating why this happened but the issue has been resolved so that future uploads should be safe.  You can also Modify your post (MORE...) and re-upload the pictures in your post.

Main Menu

Can 368 replace a 425?

Started by Joe V, September 06, 2018, 11:54:02 PM

Previous topic - Next topic

0 Members and 1 Guest are viewing this topic.

Joe V

Low mileage 78 CDV in decent shape with bad engine available locally and I have a good carburated 368 and 400 trans from another project and in need of a home.  How close to a direct swap would it be? 


Scot Minesinger

The 472/500/425/368 are the same family of engine architecture.  As engine swaps go, this should be reasonable, and simpler than a swap with a crate or other manufacturer of engines.  The climate control and ac compressor brackets will have an interface.  Also, some computer inputs, drive shaft and etc. may have some irregularities to deal with.  There was a post where a member swapped a 425 engine from a 78 into a 1982 4. powered Cadillac and he was bale to make it work, this would be easier. 

It might be even easier to buy a used good 1978 drive train and make the swap, this should not be very expensive and the cost and trouble of the interface from 1980 to 1978 may make it worthwhile.  One appeal of the 1977-79 Cadillacs is the strong 425 engine, so if you could keep it that would be great.

Fairfax Station, VA  22039 (Washington DC Sub)
1970 Cadillac DeVille Convertible
1970 Cadillac Sedan DeVille
1970 four door Convertible w/Cadillac Warranty

"Cadillac Kid" Greg Surfas 15364

Joe,
I would think you might be happier going the other way. I dropped a "high compression" 472 into my 79 "Paris" (a Coupe deVille conversion) and it is one of the sweetest combinations.  Although I believe the 368 for 425 swap would be close to seamless I doubt you will be happy with the under powered coupe.
Greg Surfas
Cadillac Kid-Greg Surfas
Director Modified Chapter CLC
CLC #15364
66 Coupe deVille (now gone to the UK)
72 Eldo Cpe  (now cruising the sands in Quatar)
73 Coupe deVille
75 Coupe deElegance
76 Coupe deVille
79 Coupe de ville with "Paris" (pick up) option and 472 motor
514 inch motor now in '73-

bcroe

I would carefully check that the AC compressor mount is not
an issue.  Are you transferring over an ECU for timing control? 
Bruce Roe

Joe V

I was hoping it would be a more of a plug and play kinds of direct swap since the engines are from the same familes, and I would have brought over all electronics that match the 368.  That would no doubt present additional challenges with wiring and connectors.  I appreciate the knowledge and experience and think the recommendation to go with a matching drive train would be the best way.  Armed with that knowledge, I'll give this opportunity a little more thought.