Could any of you guys give me the years that the 350 engine has changed letter/model designations ( example LM1, LT1, L98...... ) and what the major differences were between them ??? Just a brief history or where I can look on the web to read up on it.
Thanks !!! Fakeyankee.

 

L98 Chevy SB engines were used in 1987-1992 F-Bodies and I think the Corvette got them a couple years earlier. In 1993-1997 The 4th generation F-Bodies received the LT1. In 1998-2002 F-Bodies received the LS1 which the Corvette had already had several years prior.

Intake, heads, induction, fuel systems, computers are changed. LT1 and LS1 engines are Opti spark and have no distributor. All the above engines are hydralic roller camshaft designs. All the above engines are Chevy small block engines and many parts are interchangable between them.

Typical stock HP
L98 230-250HP
LT1 250-295HP
LS1 295-310HP

Typical stock numbers. The HP increased the newer the power plant. Search the web. You'll find many specs out there for the above engines that will give you more specific data. The above is a really general comparison.

BTW The LS1 is good for 420HP all motor with a new cam and new heads. I have an issue of High Performance Pontiac where they did this.

 

Maybe I'm wrong on this but I thought very few if any parts were interchangable between these 3 engines. I know the LT1 intake will bolt up to the L98 but not without modifying it to take a distributor. I don't think the Lt1 heads can be used on an L98 because the Lt1 uses reverse cooling. I know the LS1 is a big departure from the L98 and I don't believe anything except maybe the camshaft can be used on an L98. I also believe that virtually nothing from the Ls1 can be used on an Lt1. Maybe I'm wrong on this, can anyone shed any light on this matter?

 

Yup, the LS1 is not a SBC 350. Its a GM corporate small block 346.

 

Aren't the cams interchangable? I know some of the stuff like the LT1 intake can be used on a L98 with some minor modifications. Also I believe that I read on this site that the LT1 heads can work on a L98 with alot of work. And you do have to do something about the cooling. But it is not impossible.

 

OK......But what about the LM1 and the ones before that ??? When did the 350 make its appearance ???

 

The 350 appeared in 1967, and became common in 69. It has had dozens of "L" designations over the years.

The LM1 is a replacement truck motor, built as cheap and generic as possible, intended for fleet replacement applications. It is about the equal of the lowest performance 350 ever installed in a car through the 70s, except that the block has 4-bolt main caps installed on it. So it's most closely like a mid-70s truck 350 2-barrel. It is absolutely not a performance-oriented motor in any way, shape, or form.

The most common 70s 350 that you still see around is the L48, which was the 170 HP wonder that came in all the late 70s Z28s, Chevelles, Vettes, etc. It's about like the LM1 replacement engine, except with 2-bolt mains; it came with a 4-barrel carb.

I don't recall any of the "L" designations for 350 2-barrels, of which there were several.

The most nearly powerful 350 of the late 70s was the L82, which was "rated" at something like 195 HP IIRC. It was still pretty lame.

In the early 70s they had what was arguably the best stock 350 ever built. It was the original LT1. It had the same solid lifter cam as the 302; double-hump heads; etc. It was "rated" at 375 HP.

The late-model LT1 cam is interchangeable with the later-model Gen 1 SBC motors that have the stupid factory roller setup. I don't know for sure if you can put a factory-style roller cam in an older block, because the cam is designed for the way the later block is machined differently where the cam sprocket goes against it, for the retainer plate.

 

OK...Thanks RB. That answers alot.

 

Also, the LT1 logo designation changed when it was used the second time. It was originall marked as the LT-1 and now it's called the LT1. (or vice versa). Also, the LM1 was used in many non SS 1st gen Camaros. It was not only a truck motor.

 

To add to what RB just said..

The original LT1 engine was the hottest carb'd 350 Chevy ever offered. It had 370hp in the Corvette and 360hp in the Z28. It was litterally a stroked '69 Z/28 302. It had the same carb, intake, heads, cam, compression ratio and exhaust. Litterally the only difference was the stroke (3.48" in the 350 and 3" in the 302)

Too bad that LT1 didn't get the dual 650 cfm Holley carbs that some 302s got.... THAT would have made a really tough 350.

Oh... and the LM1 350 was an optional "HO" motor for the '80-81 Z28 Camaros... a ground pounding 190hp

 

I'll just add my $0.02--LM1 was in my 76 Camaro 4speed and in my 77 Monte Carlo. So, yours might only have 2 bolt mains