Technical GM Engine & trans have me stumped..do you know?

Hoping someone..anyone would be able to help me.. because I'm stuck..

Motor-
GM 3731548 & FII28L

Transmission-
GM 591958 & 591568

 

Going off google search info.
1957 only, 265 or 283.

Interested read
https://www.corvetteforum.com/forums/c1-and-c2-corvettes/2735561-57-283-3731548-a.html

Trans Muncie SM420
https://ck5.com/forums/threads/help-i-d-ing-a-4-speed.119611/

 

Engine block is 1957 only 283, and the heads indicate 4bbl. Can't help on the transmission...

Looks like a 327 fuelie in the background!!

 

265 or 283, I think.

The valve cover bolts look staggered. Does it have bosses for side motor mounts on the block?

 

and a 4 speed [compound low gear] truck transmission

 

Transmission looks like a Chevy 3600, 3/4 ton.

 

The transmission is a Muncie SM420 boat anchor. It's a granny 4 speed that would be in a bunch of Chevy pickups until about 1968. They work good until they don't. Then you update because parts availability is almost non-existant.

 

look up the code in the truck book. L is a light duty truck 265.

look for the casting dates to find what year it is.

 

btw the trans does not appear to have the parking brake assembly, so with all the info available, it's a 1957 Chevy 3100 or 3200 (half ton) pickup truck 265 engine/trans.

 

265


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...didn't 265's have different exhaust manifolds?,..not ram horns

 

55-56 did, but 57 saw the introduction of rams horns

And this is a 57 engine, from what we can tell.

 

Ahhh thank you.. you are awesome! I couldnt find the the "L" to save my life...
I have another engine same casting # (3731548) attached to a powerglide transmission. Its marked F422F and the date code is D187.. Which I figured was a 283 for a 1957 car/corvette..but as the casting numbers are the same would that mean its a 265? F can be a 1955 265 or a 1957 283 in the reference Im using... I probably sound so dumb..

 

F in 57 is a 283 with powerglide, 2bbl. Not a corvette engine. Not a 265.

 

...Thought ALL 283s were 'Vettes'...

 

Only when you're selling one!!!

 

I would have guessed a 265, due to the casting number, but also due to the fact it's a 2 barrel, manual trans engine (57 only). And the other engine, with the same casting number, but being an automatic engine, could have only been a 283 (again, odd 57 rules). Base V-8 engine, WITH a 2 barrel carb AND a manual trans was the 265. 283's were an option, meaning any v-8 with an automatic, 4 barrel, dual 4 barrel, fuel injection was a 283. BUT, you could have also had a 2 barrel, manual trans 283 as an option. So, that BLOCK could have been an optional 283 2 barrel truck. That's where squirrel's prefixes/suffixes really tell the story. Applies to cars AND trucks. Even confuses the Chevrolet guys. I am Butch/56sedandelivery.

 

That trans is the 3 speed with compound low (granny gear). Normal driving you take off in 2nd gear and then 3rd and 4th. Used in trucks as stated, it does have some value for the 4x4 guys that want the real low crawling gear, although they tend to like the newer SM465 over the older SM420. There is nothing really wrong with that trans for a truck, but it's not a hot rod trans. Worth more than scrap, but not a lot more.