Late Model Chevy pickup Engines

[Guyz55]

I have been told that late model Chevy pick up trucks have LS engines in ..does any one know if that's the truth . if th.at is the case would it be a good choice for a 1955 chevy 3100

I currently have a 350 and I am trying to decide whether I should replace or rebuild it ...

Thank you

[Kim57]

All late model GM pick ups have LS engines.
They are an excellent engine to swap into older cars and trucks and has been done by many guys on this site. Typically computer controlled with FI.
Can be converted to a carb though.
The 350 is also an excellent engine and works well also.
It all comes down to what you want and how much you want to spend.
Kim

[joedoh]

well, technically...

the LS name refers to the all aluminum versions in high performance cars that get high compression, aggressive camshafts, and free flowing exhaust manifold. trucks get LQ's LMs and other L variants that can be all aluminum, just aluminum heads and cast iron block, or iron blocks and heads with low rpm high torque and other parts for longevity.

they are the same engine family so parts interchange, but its kind of a misnomer. If someone advertises an LS on craigslist for $800, you can be sure its a truck motor because an LS would be 2-3000.

BUT the truck motors are a great, readily available, and inexpensive engine for any project, I saw a porsche boxster with a 5.3 in it! the power potential is amazing, there was a famous article where they turbo'd what they thought was a bone stock 5.3 to over 1000hp, turns out it was a 4.8!

keep the fuel injection! you will love it in the winter, and by the time you buy a carb, intake, ignition controller, and trans controller (if you use the truck trans) you will have spent as much or more than a turn key harness and programming.

[Dan in Pasadena]

See my build thread. My '55.2 big window has an LQ4, 4L85e and Mustang 8.8 rear in it. Though they've been refreshed/rebuilt, it has not been started yet. But compared to my old 283 with a weak cylinder, I expect the truck to be a dramatically better performer.

[mr48chev]

I'd have to agree with Joedoh in keep the FI if you go to one of those engines as that is half of what helps them do what they do.

I can't see why anyone would go to the effort of putting a 5.3 or bigger version of the engine in an early truck and regress to a carburetor. You may as well go with a bread and butter 350 and be done with it in that case.

[47 Fasttoys]

By the way '99/2000 are the crossover years '99 can go either way all 2000 and newer are LS based on the trucks. LS1tech.com is the go to source for conversion info.
Rob

[skymangs]

Try lt1swaps.com for PCM pinouts and how to build your relay pack. Brennen really knows his stuff. You won't find a more knowledgeable person in that LS industry. I know him personally.

[OrrieG]

Originally Posted by Kim57

The 350 is also an excellent engine and works well also.

And a lot of the truck 350's from 3/4 ton up are 4 bolt main blocks. Unfortunately you cannot tell from the casting numbers, I have a truck block in my Chevelle with the same casting number and 1974 date code (both came out of the 74 donor trucks) as the truck block, truck is 4 bolt, Chevelle 2 bolt. Both trucks were 1/2 tons, I suspect they may have gotten behind on engine production and just tossed in a 4 bolt to keep the line moving.