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Hello there and thank you in advance
I recently just picked up an engine and transmission out of a 73 DeVille it's a 472 with a turbo 400 and I would like to put it in my 1980 Fleetwood which currently has a 368 in it I would like to know everything I need to do to swap this engine in is it a direct fit is there any modifying I need to do etc. It's my first time taking on a task like this so any info would be much appreciated if there's any more info you need to know about the vehicles and engines please let me know
 

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Engine fits fine. Transmission does not. Original 1980 368 RWD uses a short tail TH-400.

I have detailed this swap multiple times on this site so try the search engine.

The info should really be a sticky but....
 

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Post the link for the most comprehensive swap thread, and I'll add it to the FAQ sticky!
Thanks Jay. I spent an hour so far looking and the first writeup appears to be pre-2010. Will that still exist on the site?

I could have written it again from scratch but would rather dig up 15 year old posts which may contain things I don't remember.

The other thing is I has a different account here back then. It was The Ape Man as opposed to what I'm posting under here.

It would be nice to merge these somehow but I hate to even mention that : (
 

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All I can suggest is try to find a junk 77-79 full size RWD caddy and all the parts you will need are on it.
 

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I found two threads from when when George w. Bush was president.

They both involve the subject but aren't the best for a 1980. Still some good information:


Here's what you need from memory.

Bell housing is same so existing short tail TH400 will be fine. Replace the front pump seal
whenever it's accessible during a swap like this.

Replace the 472 core "freeze out" plugs with brass types.

The 368 oil pan needs to be transferred to the 472. Along with it, the oil pickup which will need it's specialty crank bearing mounting bolt with stud relocated. Dipstick tube has to be changed also. This can be fabbed with steel fuel line is necessary.

Use the engine motor mount brackets from the 368.

The 368 oil pump housing must be swapped to the 472. Let me know if you can't find the correct gasket which is VERY thin.

Passenger side heater hose at rear of cylinder head is a large fitting on the 472. Install a Chrysler Slant 6 heater bypass hose on the fitting and leave the other hose end sticking straight up for connection to the heater control valve. Saves a lot of $#$%%. Old Gates number 20662 hose.

There's a bunch more concerning which pulley setup to use but I'm out of time today. Does your existing air conditioning work?
 

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I seem to remember mention of grinding down the upper A arm bolt to clear the larger 472 exhaust manifold...
 

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Jay many guys did that, but what I did I think is better. I milled off about 1/4" off the pad where the bolt head sits and used a shorter bolt.
 

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Exhaust is interesting for a 368 to 472 swap because exactly nothing fits.

If the 472 Y-pipe is there and no apparent exhaust leaks at the manifold to head surfaces one can use all the 472 stuff. A good exhaust shop can fab a modern cat back. You CAN keep the 368 midpipe back but that wastes potential power. I've A/Bed this and even a large single exhaust makes a noticeable difference from the 368 stuff which is all scaled down 425 stuff.

Be aware those manifold to head bolts are the single worst part of these engines. Usually they cannot be changed with the engine in the car unless they have been apart recently. Normally there are no gaskets there. That was a design goal. 30% less gasketed surfaces.

Freshening up the manifold to Y pipe studs with the engine out can also save a lot of heartache later. Use brass nuts.

Some people report needing to grind down A-arm bolt threads.

I may have sawed one or two through the years but did not need to do that on my current 1980.
 
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