Is my LT-1 out of F-body or Impala SS - Third Generation F-Body Message Boards

lbrohez · 06-01-2003, 01:53 AM

my brother has an lt-1 in our garage that he bought from a guy who had a 94 Impala SS but bought a 95 LT-1 out of an f-body, but we dont know if he just swapped the heads, and intake, or if he swapped the whole motor, and i was wondering how to tell the diffrence. i was wondering if there where numbers cast on the block or someway to tell.

Thanks in Advance

Levi Brohez

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redimpss5 · 06-01-2003, 02:05 AM

the easy way to tell, the camaro has aluminum heads and the impala ss and caprice has steel heads

lbrohez · 06-01-2003, 02:07 AM

Sorry let me clerify, we have the heads off of the Impala, but we dont know wether or not he switch the heads or the whole motor, and i would like to know which one the motor came out of.

Momar · 06-01-2003, 02:17 AM

The motor is actually mine. Lbrohez is my brother. Here is what I know. I have the Iron heads from the 94 impalla ss. I have the f body wiring harness and maf. I think I probably have the f body accessories and computer also but am not quite sure how to verify this nor does it really matter to me. The short block is what is in question.

The guy I got the motor from thought that an LT4 was put in place of his origional LT1 in his impala. Anyway, I looked at it and it was a normal alum headed LT1(I didnt tell him because I didn't feel like pissing him off). I also have the origional tag off of the junkyard motor that he was told was an LT4 and it has a engine vin of P. P is LT1, not LT4 which I already knew by looking at his car. I just want to know if there is any way to tell which short block I have because if the shop was shady enough to tell him that it was an LT4 and used all of the f body stufff like wiring and computer and MAF sensor, it wouldnt supprise me if they just swapped the heads.

The reason I want to know is because I dont plan on using the stock cam either way, but we are trying to put my brother a 350 together on a budget(90 roller motor) and figure that the LT1 cam will be slightly better than what was in the 90 caprice TBI motor. I was just curious if it is going to have the F body or B body cam. It could either be a 95 Trans Am motor, or a 94 Impala SS motor. I cant just tell by the vented opti either because all Impalla's had vented and the 95 Trans Am would have also had vented. I am bassically wondering if I can tell by numbers cast into the block or something.

Thanks

Ben

redimpss5 · 06-01-2003, 02:32 AM

ok all b-bodys got block number 10125320, the others (2 bolt mains) got block 10128374

Momar · 06-01-2003, 02:41 AM

Quote:

Originally posted by redimpss5
ok all b-bodys got block number 10125320, the others (2 bolt mains) got block 10128374

By this you mean the other 2 bolt blocks other than b bodys right? The Vettes were the only thing with 4 bolts right? Going out to check right now.

Ben

Momar · 06-01-2003, 02:44 AM

The block has a casting number of 10125327. What would this be? It doesnt match either that you listed?

Ben

90Formula-X-F · 06-01-2003, 02:47 AM

10125327...350...92-up...2 or 4 bolt ...Gen.II LT-1, reverse flow cooling
10125327...350...96-up...2 or 4bolt...Gen.II LT-4, reverse flow cooling

350 - There are two blocks, one with two-bolt mains and one with four-bolt mains. They both have the same 10125327 casting number, so there’s no sure way to know which one you have until you get the pan off. However, if it came out of a Corvette, it should be a four-bolt block, and if it came out of anything else, it was supposed to be a two-bolt. GM used the two-bolt block for everything but the Corvette because it had plenty of strength and it weighed a little bit less.

all this taken from web sites

Momar · 06-01-2003, 02:52 AM

Yes, I looked them up up on mortec and saw that. It appears that it would be the f body motor, because for that casting number that redimpss5 gave for the impala said

10125320...94-96...350..........Gen.II LT1, cast iron version, used
on "9C1" Police package, Impala SS,
Cadillac Fleetwood, Buick Roadmaster
reverse flow cooling

The other he listed said:

10128374...92-up...350..........Gen.II LT1, 53cc, angle plug,
aluminum, reverse flow cooling,
175/68cc ports

It looks like it actually listed alum or iron heads for the other, but I would assume that since the casting number I have was also used for the LT4 that it would have been the f body version. Any other input is appreciated.

Ben

Momar · 06-01-2003, 10:41 PM

Anyone know for sure?

Ben