L20B M1 block

[RedStar620]

I pulled the engine out of my '78 620 and noticed that it has an "M1" code on the side of the block behind the driver's side engine mount. The pads for the engine code and serial number are on the passenger's side of the block, like on all L engines. The serial number is #286093. I've heard of the M2 L20B blocks, but never heard of an M1. Has anyone seen an M1 L20B block and how rare are they?

[datzenmike]

I have a Z24 block .... M3

I have  a Z22 from a 720 block... nothing on it.

Have an L20B from a 620 don't know the year but had silver paint on it with nothing on either side, an L20B definitely from a '79 620 and says M2 and another L20B block but can't get to it.

 

This tells me that I have too much shit laying around.

 

The M1 sounds familiar. My 710 has an L20B I'll take a look tomorrow. It would be a '76. I think the M1 is a later casting.

[paradime]

I found "M1 on LD20 on the intake/exhaust side of the block" It's in the 10th reply for a hybridZ conversation on "M" notation on L-series blocks? https://forums.hybridz.org/topic/74905-m-notation-on-l-series-blocks/

 

The diesel LD20 was a modified petrol engine.

 

Hope this helps'