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1978 Trans Am L78 (400 C.I.D) Or L80 (403 C.I.D) - How To Tell?

gregbert78

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I just received the information packet about my car from PHS Muscle Cars.

Though I was hoping for more info, it was still well worth the $85.00 research cost I had to pay.

Thanks, PHS!

You can order a packet for your car at http://www.phs-online.com/services.htm

Though I did receive the Dealer Invoice on my car, it doesn't tell me a ton other than the options.

I'd like to know if my car originally was an L78 or an L80? Why? Collectability.

In 1978 made 83K fewer cars with the L80 403 ci engine than they did with the L78 with the 400 ci engine.

Can anybody tell me how to go about finding this out?

Could you also tell me how I find if the engine in my car is original?

I'm uploading the dealer invoice for those of you who do not know what they look like and also including a pic of my car because, well, just because they're all so cool, and we love them all!

TransAmOriginalBuildSheet.JPG


TA_Left_verySmall.jpg
 
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gregbert78

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I also posed the L78/L80 question to those folks at PHS Muscle cars.

Here is their answer. "In 78, there will be a partial VIN on the block.

The Z in the VIN lets you know you have the Pontiac 400. the L80 is the Olds engine (which would have a K in the VIN)"
 

gregbert78

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Tbone

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Your welcome, w regard to is it the correct engine in the car.

Here are some ballpark toys.

A 403 is a version of the 350 & much smaller.

Google pics of a Pontiac 400 & a 403. Pretty easy to tell the diff.

Also, Google casting # for where to look on Pontiac 400 for casting #.

Check around on your block for casting #’s once you believe/decide it is a 400.

When you know, let us know.

There r a site that’ll give you what year 400 it is.