1986 420 SEL block under 1983 380SL heads ?
 

What I'm trying to find out is, can I install a 1986 thro' 1992 420 SEL short block under a set of 1983 380Sl heads and parts to instal in a 1983 107 380SL?

I'm 90% sure it will all fit and marry up...with the p/s pump...a/c compressor, flex plate, etc.....but perhaps someone in the collective can give me any reason why it might not be possible.

Why? Because owner blew motor by forgetting to fill with oil after oil change :rolleyes:
I have two newly fully rebuilt 380/107 116 engine heads with new cams, followers and lifters....owner said he'd like a little more power too.

If not, I have to find a solid 116 block.

Anybody ?:)


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I don't see any issues, just have to adjust the fuel delivery properly.

Fueling is no problem...it is CIS-e o2 controlled....just worried about building it up to find I can't match all the other bolt on's....:pleased:

I figure the extra cubes would change up the CO only. :)

I have chased this some. The 380/420 heads have diffent PN's. All you need is one bolt hole to be different. This is what keeps scareing me off.

Agree with Chuck
 

The cc may be different as well as mating issues. Because MB upped the 116 to the 117 500 then, the 560. I think the 420 came later. Therefore, I would think the 500 engine would be a closer part swap for the 116 380 as compatability goes. Let us know!

My look up of the engine spec' tell me the 116 380 and 420 engines have same power ...218hp, except 420 does it at 300 rpm less. 420 is same bore but longer stroke.

With all the possible mismatches, I am going to find a 380 116 block and run a dual 2 1/2 inch exhaust.:thumbsup:

The 420 block with 117k I found on eBay was $375.00....cheap enough.

But cheap is where I usually find it gets expensive.:rolleyes:


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i have successfully done this swap.use the 380 intake and heads on a 420 block.it works well and definately has more power.

When you say 'successfully'...you mean, no problems at all in a 1983 380SL ?

that is correct,no problems at all.

Another question
 

David -

Thanks for the information - this really increases the options for 380SL's.

Do you think you can use a 420 block and heads with a 380 intake/injection and exhaust?