Abdullah

iTrader: (2)

what i know it will fit, am i correct?

i'm trying to find a budget 396 kit (3.875" crank, 6.0" rods, 11.5:1 compression
4.030" pistons) that i want to install in my 1996 impala SS. i don't care too much about if the crank or pistons are forged or not but i want the kit to be in the $700-1000 range balanced and 11.5:1 compression pistons. i don't intend to use nitrous.

let me see what you think.

thanks.

Formula350

iTrader: (3)

Yea, we share the same rotating assembly as the GEN I.

Don't know if the block has to be clearanced for the longer stroke or not. I thought they did on GEN I, but might have redesigned that bit in the block too.

RamAir95TA

iTrader: (2)

Expect to pay at least double what you anticipate on paying in parts for the extra machine work needed to run a 396. This includes boring with torque plates, line-honing, clearancing for the stroke, cleaning and assembly of the block. It is not possible to build a 396 with $1000.

Do you have heads and valvetrain ready? A 396 on stock heads and cam will be an absolute dog. What else do you have done?

Pistons and rods will work from a Gen I, but typically Gen IIs use a 2-piece rear main seal. LT1s use a one piece, so no, we do not share the same rotating assembly exactly, as you need a crank designed for a one-piece rear main seal. Not to mention, all stroker motors require clearancing of the block.

Formula350

iTrader: (3)

News to me that GEN II uses a 2 piece. The 96 I refreshed had a 1 piece. The 92 TBI I'm doing is 1 piece, my 91 L98 was 1 piece. I believe all 86+ 4.3L V6 and V8 are 1 piece. Even factoring in your typo, assuming GEN II was supposed to be GEN I, 86-99 is 1 piece and that's quite a span of year. Sure, GEN I's have many more year of service, not sure if I'd use "typically" though. Even if the truck blocks are considered GEN II like our LT1s, they're all 1 piece.

SS RRR

iTrader: (2)

If using a 2-piece crank then you would have to get an adapter for the seal, you would have to use a Gen I flywheel and clutch. I was exploring doing this as well when FedEx lost my crank and I was waiting months before it finally arrived, but was told over and over the hassle just isn't worth it.
Contrary to popular believe the machine work for a 396 is really no different than a 383. The introduction to the GenII was the LT1. Not the 1-piece main seal.

GIZMO

iTrader: (8)

LTX motors are GEN II.

In answer to the original question, a one piece main seal crank for a GEN I SBC will fit an LT1.

Paul Bell

iTrader: (9)

SBC pre 86 are considered gen 1. SBC afterwards with one piece rear main seals are considered gen 2. LT1/4 are also considered gen 2 as they have one piece rear main seals.

Anything LS1/6 is gen 3. Anything LS2/3/7 is gen 4

SS RRR

iTrader: (2)

The Gen II was the intro to the reverse coolant flow LT1.

GIZMO

iTrader: (8)

The LTX motors are GEN II. I have never seen any small block with conventional cooling listed as a GEN II in GM literature. The Vortecs came out in 1996 with a lot of GEN II technology. Please post up any GM info that you have that lists conventional small blocks as GEN II.

SS RRR

iTrader: (2)

That is what I'm saying for the third time now. The intro to the GEN II engine is indeed the start of the LT1. Not sure where I stated any different or where your misunderstanding is.

Formula350

iTrader: (3)

That's my understanding as well, 86+ is GEN I with the exception being LT1s. I've actually not heard of any of GMs other 8s being a GEN II, even those 96+. So Paul, I'm not sure where you had heard of 86+ being GEN II (at the least up to 96).

I know Wiki isn't the be-all end-all for info but:

-Chevrolet's small-block V8 is not a single engine but a series of famous automobile engines built on the same basic small (for a V-8) engine block. Retroactively referred to as the "Generation I" small-block, it is distinct from subsequent GM "Generation II" LT and "Generation III" LE engines.


-Finally superseded by GM's Generation II LT


-Confusion with LT and LE engines

The original Chevrolet-designed small-block is a specific family of engines manufacturerd originally in 1955 and installed as production powerplants by GM for 48 years.

...<snip>...
* For more information on the Generation II small-block V8s, which differ mainly in their reverse-flow cooling system, see the GM LT engine.



This last line on the page I think is key though....

-1996 - This was the last change for the Generation I engine, and continued through the end of the production run in 2003; all 1997-2003 Generation I engines were Vortec truck engines. The cylinder heads were redesigned using improved ports and combustion chambers similar to those in the Generation II LT1, resulting in significant power increases. The intake manifold bolt pattern was also changed from four bolts per cylinder head instead of the traditional six.



Now I didn't post all that in the "I told you so" tone, as I know it will come across like :\ I just went to Wiki and noticed a lot of info that doesn't match up with what you said, and that's the only reason I posted it. Previous to going to Wiki all I was going to post was above the "be-all end-all" line.

engineermike

I always understood...

Old 2 pc rear seal, perimeter bolt valve covers, etc = Gen 1
86+ one pc rear seal, center bolt valve covers, etc = Gen 1+
LTx = Gen 2
LSx = Gen 3