Has anyone ever seen a 442 with a L31 engine in it? I knew they came with the W32, and also the W30 machines had something special - I do not know the designation for that engine.
But here is one with an L31.
1969W3155 sent me this buildsheet:

 

I sent a copy of the build sheet to WMachine, he also has a build sheet for another 442 with the L31 option listed. He is currently digging up info on this, so hopefully he will be able to give some insight into this.

 

My buildsheet (Fremont) for my 70 442 says:

"N10-L31 Dual EXT"

 

It's my understanding that the W-32 was an option code for the 4-bbl. 455 for the SX and not the motor code for the standard 4-4-2. I realize that may appear confusing, and I don't have access to any paperwork at the moment to delve into the topic a bit more.

 

The L31 is the engine code for the 365 hp engine for the 88/98 line, and the midyear changeover engine for the '70 SX, (10.25:1 510lbft) But, it shows up on some 442 build sheets, which should be the 10.50:1 and 500 lbft. 365 hp engine.

 

Check out this truncated item I cut from the GM Heritage Center:

http://www.gmheritagecenter.com/gm-h...2_Info_Kit.pdf

 

I wonder if the L31 really is the same as the W-32 and they were measured differently based on their different applications?

 

Yes, in 1970 the L31 was the *RPO* code for the 442 engine. And also the *RPO* code for the 365 hp 455 that went into the big cars. Different engines.
So as you can see, the RPO engine code doesn't really *directly* identify the engine. (And on top of that, the RPO codes are not even the same from year to year).
So the RPO code is in reality a *group* number of sorts. This is illustrated in the assembly manual chart here, notice the "UPC Group" column. The real identifier with the engines is the 2 letter Production Code, or what becomes a "Broadcast Code". Notice on the build sheet that the RPO code L31 is mentioned with the options. But look up where the engine id block is and you'll see (in this case) the "TV" Broadcast Code which in this case is for the 442 engine with an auto and AC.
Think of it this way, just like there are different "L31 engines" there are different 442 engines and even 2 different W30 engines.

I've also attached the chart from the Chassis Service Manual to point out that it creates some confusion due to some errors. The 442 engines incorrectly listed under the 10.25 455. Rather than try to sort that all out, suffice to say the 2 letter codes are correct.

 

Nice, thank you.

 

Ahhh!! Fantastic! A light just went on.
I now must go back and review everything I have written about engine options, and I will never use the RPO codes to identify them in isolation again.

Thanks WMachine!

 

Thanks Kurt, I had forgotten about the 2 letter production code.