5.6L transplant in 4.2L chassis

[420SEL]

Just wondering if anyone has ever done this.
Would it be as simple as transplanting the engine, tranny, and electronics. Or would all powertrain parts transferring power to the rear need to be upgraded as well.

Anyone know the differences between the transmissions in these 2 vehicles?

Just curious as I am thinking of a rebuild or swap.

Thanks all!

[dtkw]

I believe both engine are pretty identical except the size as 4.2 vs 5.6. They share a lot of parts like water pump...etc.

[jhodg5ck]

transmission is all but identical, just keep the fuild fresh (every 15-20K). You'll need the 560 EZL and possibly some wiring but other then that it should be fairly straight forward.

Jonathan

[420SEL]

Seems to be pretty straightforward. Thanks for the info guys, will seriously consider this.

[cyberdrakon]

Not the same. 4.2 is same as 380, 5.6 is same as 5.0.

[NordRhein]

cyberdrakon - 3/2/2005 5:49 PM

Not the same. 4.2 is same as 380, 5.6 is same as 5.0.

The 500 came first in the late 1970's, then the 380 came out as an underbored 500. Then they punched out the 500 to get the 560 and since the 380 was, shall we say "tired" for the US market they made a 420. All are from the same block, EUROs have different (and better) exhausts, different water pumps etc. but it all bolts on. Transmissions are all exactly the same box with minor tweaks to make it easier for the production line - i.e. they tweak them before installation and stamp a diff number on them so the production line doesn't have to do anything but install them. As for the fuel injection systems, ANY system will work on ANY engine so long as all the parts for that system are there. Yes, that means with the fuel distributor from my old 1980 500SEL you could run a 1991 560SEL with NO pollution controls whatsoever - or retrofit backwards if you're so inclined.
So for the people who get lost - the answer is yes, the engines will swap.