My 89 Formula 350 has two vin numbers

My 89 Formula 350 has two vin numbers.One on the body that we all know.A vin sticker that was placed on my under the hood,that sticker matches the factory stamp on the engine put on by the factory.Which is a 305 5.0.Nice.The side of my Firebird say Formula 350.Body vin say 5.7 .Gm just keeps telling me that how do we know someone didnt change the motor.I gave them both vins there from the same factory same year in vin.Nice car.Come on Gm help me out.  

If the VIN sticker on the hood does not match the one on the body, the hood came from another car.  If that number matches the engine, the engine did too, same car.

Your car may have been heavily front end damaged and repaired using parts including the engine) from another car hit in the rear. Happens all the time.

I would just be curious if your title has the VIN from the body, and if the title says SALVAGE on it. That would explain everything, we call that a "rebuilder". Its where you take two cars and make one. They may even have a clean title.  

vin on hood matches engine not the body,I would agree with you but,both numbers came from the same plant.car go all over the world.They couldnt get the hood and engine from the same plant.If you break down both vins same year same plant.the sticker that they placed on my hood should have been on the engine .  

Nothing on title about salvage.but from the same plant.  

I guess I don't understand.

Humor me... If two cars are made at the same plant in the same year but with different engine options, and they end up being put together to make one car later on, what is so unusual about that? A car has to be really popular to be built at more than one or two plants.

I say all that matters is that the VIN on the cowl matches the title. Disregard anything on the hood. Any other numbers anywhere on the car are of no legal consequence. For ordering parts and such, you may want to ID the engine with casting #s, screw the VIN and stampings. Thats about all I can offer.  

I can't recall for sure about the third gen cars, but second gen f-bodies were only built at Van Nuys California and Norwood Ohio. The fourth gens were only built at St Therese Quebec here in Canada. I highly doubt that your car was built on the assembly line with two VINs. So it is very possible that your car was involved in an accident that required a new front clip and engine, a donor was found that was the same year and it was repaired using all the pieces from that donor (which had a very great chance of being built at the same plant) and if the car was fixed under insurance coverage, there will be no "salvage" on the title.  Look for signs of repaint on the front clip. Order engine parts according to the VIN on the engine so you get the correct parts and order all other parts by the body VIN.
Steve  
A little help... 'cause we don't all have to learn the hard way!

I checked for repaint.I just think the engine got swapped at gm.And if the car was in crash i could tell.The car has the formula 350 stickers on the doors.why would they put a 305. back in. whats chance of the hood being the same color.The sticker would have been painted over.I bought this car from a farmers son,he drove it on the farm,I saved her from his dui buthead.He said he was the second owner.I titled it.Im the 3rd owner.Gm told me to bring it down to the dealer.I wanted to restore the car.Im restoring my 83 transam and now wanted a formula 350 with t-tops.I cant even get a 350 with out a core of a 350.I just want gm to put the right motor in my car.  

Don't take this the wrong way, but you want GM to replace the motor in a 20 year old car AND you are the third owner? You are dreaming my friend! Even if it was a factory screw up, GM isn't going to do anything after twenty years and three owners. Besides, you are never going to get the original 350 for the car from GM, so regardless of what 350 you put in, the best you can hope for is to find a correct casting number block with a correct date code, neither of which will make the car "numbers matching". Is the car an automatic or manual trans? The 350 was never available with a manual trans until the 93 LT1 cars came out, the 305 could be either 4 speed auto or 5 speed manual. Is the engine in the car a TBI (throttle body injection) or TPI (tuned port injection)? The 305 was available either way, the 350 was only available in TPI. What are the first 10 digits of both VIN's? I don't need/want the rest of the numbers (those will identify the actual car and I don't want to invade your privacy), from the first 10 digits I can try to decode what the car should have.
Steve  
A little help... 'cause we don't all have to learn the hard way!

+1    

+2  
professional hi-performance engine builder.
Horsepower sells engines and torque wins races

Body 1G2FS2188KL2
motor hood 1G2FS21F3KL2
all but the last 5 numbers  

+3  

Body 1G2FS2188KL2
motor hood 1G2FS21F3KL2
all but the last 5 numbers  

Sorry it took awhile to get back to you. Here's what I found, obviously both VIN's are virtualy identical except the 8th digit engine codes (8 for the body and F for the hood and engine)and presumeably the last five numbers are different in each VIN, indicating two separate vehicles. You didn't mention which transmission the car has in it so I'll give you all the info I found. The VIN on the body (8 for the L98 350) indicates that the car was indeed a 350 powered car. There were two possibilties for the L98 350, a 230hp version that came with an automatic and 2.77 rearend gears or a 240hp version for auto with 3.27 gears. Don't take this as carved in stone, but I believe the difference was in the exhaust system, either single or dual catalyst.
The VIN on the engine and hood indicates an LB9 305 which had three possible ratings: 195hp(auto), 220hp(manual w/3.08gears) or 230hp(manual w/3.45 gears). The best assumption I can give is that the car was damaged and repaired with parts from a same color donor. If you can't trace the previous owners to find out for sure, then you have a mystery.
Steve  
A little help... 'cause we don't all have to learn the hard way!

+1  
professional hi-performance engine builder.
Horsepower sells engines and torque wins races