Topic: What kind of Motor is in my Trans Am ?

[helroha]

Hello there,
I am new to this forum and I have a problem with my 1979 Trans Am
It should have a normally installed an Oldsmobile 403 engine
but I think that's not true.

The number on the bottom left to the engine block is: 31M158386
the last 6 digits of the VIN number do not match the dashboard agree

Who can tell me what engine I have in my Trans Am?

please excuse my bad english

Helmut (Germany)

[SA74SD]

I hope this helps you. I believe what you have is a VIN derivative. Your engine probably came out of a 1971 Oldsmobile assembled in Lansing, MI.       
 
This number should take the form of "35Mxxxxxx" where:
 3 = Oldsmobile division.
 5 = year of manufacture (8='68, 9='69, 0='70, ..., 4='74, 5='75, 6='76, etc).
 M = location of manufacture (M = Lansing, B=Baltimore, X = Kansas City, Z = Fremont, CA, etc).
 xxxxxx = last six digits of VIN of car that motor originally came in (original car's sequential production number).

[Wallington]

A good start. Just read the casting numbers for the block next to the oil giller tube behind the water pump plate. And of course the large number on corner of heads.

[helroha]

Thanks for the quick help :-)
that helps me in any case,

I shall examine the other numbers and continue to report
then possibly it's a 350 engine ??
next saturday i can check the other numbers

greetings
helmut

[helroha]

Thanks for your help, I have found that I have a Oldsmobile 350 engine installed  built in 1971   

[Wallington]

Much better than a '79 350 Olds. Hopefully the older engine in newer car won't get you into trouble.

[helroha]

  In any case, I'll have the same fun with the car even if another engine is installed