Engine number frame match

[pflaming]

How does one dterminemif the engine is original to the chassis?

[pflaming]

"  On a Plymouth, that number begins with "P15" followed by additional numbers.

These will be the same numbers that were stamped on the side of your original engine.  If they don't match.....the engine has

 been changed/replaced with something." 

 

I found the answer. Will check out the numbers later this morning. 

[dmartin_egroup]

I do not have access to earlier discussion of this topic.  I think you say we must match the engine number to a number on the chassis.  WHERE ON THE CHASSIS MUST WE LOOK?  My car is a 1937 Plymouth, it may be different from a P15.   Thanks much!!