By "original" what exactly are you looking for? Unless you can find the engine with the same VIN stamp that your vette came out with you won't have an original. From the numbers you posted, it indicates that it is possibly from a vette.Have 66 vette ,trying to find origianl engine. Found one with cast #3858180 and another number FT228HD and finally one other number
5D125048. Is this possibly a 66 vette 327?